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| NJU6052 PRELIMINARY White LED Driver with Automatic Dimming Control ! GENERAL DESCRIPTION The NJU6052 is a white LED driver with an automatic dimming control. It contains an output driver, a PWM controller, a luminance sensor control (power supply for sensor & A/D converter), a step-up DC/DC converter, a serial interface, etc. The output driver ensures a 60mA maximum capability which allows the connection of 12 white LEDs (4 series x 3 parallels). Depending on the ambient light sensed with an external luminance sensor, the PWM controller controls PWM duty in 8 steps preselected out of 64 steps. In addition, the frequency of the DC/DC converter is high so that it permits the use of small, low-profile inductors and capacitors to minimize the footprint in space-conscious applications. All of these benefits make the NJU6052 suitable for the battery-powered portable applications such as a cellular phone, a camcorder, PDA, etc. ! PACKAGE OUTLINE NJU6052KN1 NJU6052V ! FEATURES # Drives up to 12 white LEDs (4 series x 3 parallels) VSW = 18.0V(Max.), IOUT = 60mA # Built-in PWM Dimming Control (Selectable 8 out of 64 steps) # Built-in Luminance Sensor Control (Power Supply for Sensor & A/D converter) # # # # # # (No MPU-access required after initial setting) Built-in Temperature Compensation Circuit to Suppress the Characteristic Degradation of LEDs Uses Small Inductor and Capacitors 1.8V to 3.6V Operating Voltage for Logic Circuits (VDDL) 3.0V to 5.5V Operating Voltage for Step-up Circuits (VDD) CMOS Technology Package : QFN28 / SSOP20 Ver.2003-10-23 -1- NJU6052 ! QFN20 PIN CONNECTIONS (TOP VIEW) VSS VSS VSS REF NC NC CX NC FB VOUT SW SW SW NC NC VSO SENS RSTb SCK DATA NC ! SSOP20 PIN CONNECTIONS (TOP VIEW) NC TEST NC VDD VDDL REQ NC VOUT FB VSS VSS VSS REF CX VSO SENS RSTb SW SW SW TEST NC VDD VDDL REQ DATA SCK -2- Ver.2003-10-23 NJU6052 ! PIN DESCRIPTION QFN 4 5 25 26 27 10 9 2 6 12 11 24 23 18 19 20 16 13 17 1 3 7 8 14 15 21 22 28 No. SSOP 6 7 1 2 3 10 9 4 8 12 11 20 19 16 17 18 14 13 15 SYMBOL VDD VDDL TYPE Power Power DESCRIPTIONS VDD Power Supply - Power supply for step-up voltage VDDL Power Supply - Power supply for logic voltage. - Relation:1.8V VDDL VDD should be maintained. Switch - All these terminals should be connected together. Shift Clock - Serial data is latched on the rising edge of SCK. Serial Data Test - This terminal must be open. Data Request "L" : Writing command data "H" : Reading sensor data Luminance Sensor Connection Reset - Active "L". Output - This terminal is connected to LED anode. Feedback Ground - All these terminals should be connected together. Oscillator Capacitor Connection / External Clock Input VSO Power Supply - Power supply for luminance sensor - 2.4V typical Reference Voltage - This terminal must be open. SW SCK DATA TEST REQ SENS RSTb VOUT FB VSS CX/TCLK VSO REF Input Input Input / Output Output Input Input Input Input Input Power Input Output Input 5 NC - Non Connection - These terminals must be open. Ver.2003-10-23 -3- NJU6052 ! BLOCK DIAGRAM L1 VDD VSO Regulator SW D1 VOUT C1 SENS A/D Converter C2 Register PWM Controller A1 FB VDDL REQ SCK DATA Reset Serial Interface Logic REF VREF A2 RLED RSTb CX/TCLK OSC VSS TEST -4- Ver.2003-10-23 NJU6052 ! FUNCTIONAL DESCRIPTONS (1) LED CURRENT CONTROL The NJU6052 incorporates the LED current control circuit to regulate the LED current (ILED), which is programmed by the feedback resistor (RLED) connected between the FB and VSS terminals. The reference voltage VREF is internally regulated to 0.6V typical and connected to the positive input of the built-in comparator A1. Formula (1) is used to choose the value of the RLED, as shown below. RLED = VREF I LED --- Formula (1) VREF=0.6V (TYP.) Referring to the block diagram is recommended for understanding the operation of the LED current control. The ILED is the constant current programmed by the RLED. When the feedback voltage on the FB terminal reaches above the reference voltage VREF on the REF terminal (i.e., ILED is above the level programmed by RLED), the output capacitor C2 delivers the ILED. Once the feedback voltage drops below the reference voltage (i.e., ILED drops below the level programmed by RLED), the comparator A1 detects it and turns on the internal MOS switch, then the current of the inductor L1 begins increasing. When this switch current reaches 720mA and the comparator A2 detects it, or when the predetermined switch-on-period expires, the MOS switch is turned off. The L1 then delivers current to the output through the diode D1 as the inductor current drops. After that, the MOS switch is turned on again and the switch current increases up to 720mA. This switching cycle continues until the ILED reaches the level programmed by the RLED, then the ILED is maintained constant. When the feedback voltage is less than 1/2*VREF, the current limit of the MOS switch is reduced to 500mA typical. This action reduces the average inductor-current, minimizes the power dissipation and protects the IC against high current at start-up. The total forward-voltage of the LEDs must be greater than the power supply voltage VDD, otherwise the LEDs remain lighting up, being out of control. (2) OSCILLATOR The built-in oscillator incorporates a reference power supply, so its frequency is independent from the VDD. The frequency is varied by the external capacitor CX, as shown in Figure 7. (3) LUMINANCE SENSOR CONTROL The luminance sensor control circuits consist of the power supply for sensor and the A/D converter. The A/D converter senses the voltage on the SENS terminal and selects 1 out of 8 registers (PWM REGISTER 0-7). And the data in the selected register is reflected to the PWM duty (PWM dimming control). The contents of the registers can be programmed through the serial interface, in other words, the dimming control is user-settable. The voltage sense and the register selection are updated at regular intervals, and the interval period is set by the "DIVIDE" bits. The selected register is held by setting "1" at the "HOLD" bit of the command data. Ver.2003-10-23 -5- NJU6052 (4) PWM DIMMING CONTROL By setting the duty data at "PWM REGISTER" bits, 8 out of 64 registers are assigned to the PWM REGISTER 0-7. The PWM duty is changed depending on the register selected by the SENS voltage. The relation between the PWM REGISTER and its duty is shown below. TABLE 1 PWM DUTY vs. PWM REGISTER REGISTER DUTY REGISTER 0,0,0,0,0,0 OFF 0,1,0,0,0,0 0,0,0,0,0,1 3.13% 0,1,0,0,0,1 0,0,0,0,1,0 4.69% 0,1,0,0,1,0 0,0,0,0,1,1 6.25% 0,1,0,0,1,1 0,0,0,1,0,0 7.81% 0,1,0,1,0,0 0,0,0,1,0,1 9.38% 0,1,0,1,0,1 0,0,0,1,1,0 10.94% 0,1,0,1,1,0 0,0,0,1,1,1 12.50% 0,1,0,1,1,1 0,0,1,0,0,0 14.06% 0,1,1,0,0,0 0,0,1,0,0,1 15.63% 0,1,1,0,0,1 0,0,1,0,1,0 17.19% 0,1,1,0,1,0 0,0,1,0,1,1 18.75% 0,1,1,0,1,1 0,0,1,1,0,0 20.31% 0,1,1,1,0,0 0,0,1,1,0,1 21.88% 0,1,1,1,0,1 0,0,1,1,1,0 23.44% 0,1,1,1,1,0 0,0,1,1,1,1 25.00% 0,1,1,1,1,1 DUTY 26.56% 28.13% 29.69% 31.25% 32.81% 34.38% 35.94% 37.50% 39.06% 40.63% 42.19% 43.75% 45.31% 46.88% 48.44% 50.00% REGISTER 1,0,0,0,0,0 1,0,0,0,0,1 1,0,0,0,1,0 1,0,0,0,1,1 1,0,0,1,0,0 1,0,0,1,0,1 1,0,0,1,1,0 1,0,0,1,1,1 1,0,1,0,0,0 1,0,1,0,0,1 1,0,1,0,1,0 1,0,1,0,1,1 1,0,1,1,0,0 1,0,1,1,0,1 1,0,1,1,1,0 1,0,1,1,1,1 DUTY 51.56% 53.13% 54.69% 56.25% 57.81% 59.38% 60.94% 62.50% 64.06% 65.63% 67.19% 68.75% 70.31% 71.88% 73.44% 75.00% REGISTER 1,1,0,0,0,0 1,1,0,0,0,1 1,1,0,0,1,0 1,1,0,0,1,1 1,1,0,1,0,0 1,1,0,1,0,1 1,1,0,1,1,0 1,1,0,1,1,1 1,1,1,0,0,0 1,1,1,0,0,1 1,1,1,0,1,0 1,1,1,0,1,1 1,1,1,1,0,0 1,1,1,1,0,1 1,1,1,1,1,0 1,1,1,1,1,1 DUTY 76.56% 78.13% 79.69% 81.25% 82.81% 84.38% 85.94% 87.50% 89.06% 90.63% 92.19% 93.75% 95.31% 96.88% 98.44% 100.00% The relation between the PWM REGISTER and SENS voltage is reversed by the "REV" bit, as follows. TABLE 2 REV vs. PWM REGISTER REV PWM REGISTER PWM REGISTER0 PWM REGISTER1 PWM REGISTER2 PWM REGISTER3 PWM REGISTER4 PWM REGISTER5 PWM REGISTER6 PWM REGISTER7 PWM REGISTER7 PWM REGISTER6 PWM REGISTER5 PWM REGISTER4 PWM REGISTER3 PWM REGISTER2 PWM REGISTER1 PWM REGISTER0 0 1 Note 1) For the information on the relation between PWM duty and LED current (ILED), refer to "(9-1) PWM DUTY and LED CURRENT". Note 2) For the information on the relation between SENS voltage and PWM REGISTER, refer to "DC ELECTRICAL CHARACTERISTICS". -6- Ver.2003-10-23 NJU6052 (5) SERIAL INTERFACE (5-1) SERIAL DATA WRITE The serial data is latched into the shift register on the rising edge of the serial clock (SCK), and determined on the rising edge of the data request (REQ). The serial data format should be the MSB first. For COMMAND data transmission, the command data 1 (CMD1) and the command data 2 (CMD2) should be continuous. The CMD1 is first, then the CMD2. If only 1-byte data is transferred, this data is recognized as the CMD1. Do not transmit 3 bytes or more, because 3rd data is used only for maker test and the 4th and later are ignored. If it's absolute necessary to send the 3 bytes or more in the user's application, the only data (0,0,0,0,0,0,0,0) as the 3rd data can be accepted. For DUTY data transmission, 8 bytes for PWM REGISTER 0-7 should be continuous. The order is : PWM REGISTER 0, 1, 2, 3, 4, 5, 6 and 7. If 7bytes or less are transferred, all bytes are accepted. And if 9 bytes or more, the 9th and later are ignored. Note that the data should be in 8*n bits (n=integer number), otherwise it may cause malfunctions. And the SCK should be "0" when the REQ is changed. SERIAL DATA FORMAT TABLE 3-1 Command Data 1 B7 B6 B5 B4 0 SOFF BRIGHT TABLE 3-2 Command Data 2 B7 B6 B5 B4 0 0 0 0 TABLE 3-3 Duty Data B7 B6 B5 1 * B3 B2 STBY B1 HOLD B0 REV B3 0 B2 0 B1 B0 DIVIDE B4 B3 B2 PWM REGISTER B1 B0 FIGURE 1 REQ COMMAND DATA TRANSMISSION SCK DATA B7 6 5 4 3 2 1 0 B7 6 5 4 3 CMD2 2 1 0 CMD1 FIGURE 2 REQ DUTY DATA TRANSMISSION SCK DATA B7 6 5 4 0 3 2 1 0 B7 1 6 0 B7 6 0 6 B7 6 7 PWM REGISTER Ver.2003-10-23 -7- NJU6052 (5-2) SENSOR DATA READ The DATA terminal becomes output state by setting the REQ terminal to "1" after the command data transmission. And the sensor data is read out, synchronizing with the SCK. The bit number corresponding to a selected register is "1" and the others are "0", as shown below. FIGURE 3 SENSOR DATA READ (REV=0, PWM REGISTER4 selected) REQ SCK DATA B7 Command Data (Input) 0 1 2 3 4 5 6 7 Sensor Data (Output) (5-3) SOFF and BRIGHT By setting "1" at the SOFF bit, the luminance sensor control is disabled and the PWM duty is controlled by the BRIGHT bits, as shown below. TABLE 4 SOFF and BRIGHT SOFF BRIGHT REV 0 - 0 1 000 001 010 011 100 101 110 111 - PWM REGISTER PWM REGISTER0 PWM REGISTER1 PWM REGISTER2 PWM REGISTER3 PWM REGISTER4 PWM REGISTER5 PWM REGISTER6 PWM REGISTER7 PWM REGISTER0 PWM REGISTER1 PWM REGISTER2 PWM REGISTER3 PWM REGISTER4 PWM REGISTER5 PWM REGISTER6 PWM REGISTER7 Note 1) When SOFF="0", luminance sensor control is enabled and PWM REGISTER is selected according to SENS voltage. Note 2) For the information on the relation between SENS voltage and PWM REGISTER, refer to "DC ELECTRICAL CHARACTERISTICS". (5-4) STBY By setting "1" at the STBY bit, the NJU6052 goes into the standby mode, as follows. - DC/DC converter, oscillator, reference voltage generator, and power supply for sensor are halted. - The contents of PWM REGISTER are maintained. - Luminance sensor control circuit is initialized. -8- Ver.2003-10-23 NJU6052 (5-5) HOLD By setting "1" at the HOLD bit, the selected PWM REGISTER is held and the luminance sensor control cannot be used. In other words, this setting works so that the luminance of the LEDs doesn't change even if the SENS voltage changes. The selection is initialized to the PWM REGISTER 0 by the reset. And when the standby is released, the selection is initialized to the PWM REGISTER 0 at REV="0" or the PWM REGISTER 7 at REV="1". (5-6) REV By setting "1" at the REV bit, the correspondence between the PWM REGISTER and SENS voltage is reversed. TABLE 5 REV REV 0 1 PWM REGISTER PWM REGISTER0 PWM REGISTER1 PWM REGISTER2 PWM REGISTER3 PWM REGISTER4 PWM REGISTER5 PWM REGISTER6 PWM REGISTER7 PWM REGISTER7 PWM REGISTER6 PWM REGISTER5 PWM REGISTER4 PWM REGISTER3 PWM REGISTER2 PWM REGISTER1 PWM REGISTER0 (5-7) DIVIDE By setting the DIVIDE bits, the sensor-sampling-time (tSENS) and PWM frequency (fPWM) are changed. Note that these parameters are varied depending on the oscillation frequency (FOSC). The formula (2) gives the sensor-sampling-time. t sens = TABLE 6 2 (17 + N ) f OSC (sec) --- Formula (2) SENSOR SAMPLING TIME N 0 1 2 3 FOSC 100kHz 200kHz 0.655 400kHz 0.328 0.655 800kHz 0.164 0.328 0.655 DIVIDE 00 01 10 11 1.311 2.621 5.243 10.486 1.311 2.621 5.243 1.311 2.621 1.311 UNIT : sec Ver.2003-10-23 -9- NJU6052 And, the formula (3) gives the PWM frequency. f pwm = TABLE 7 f 1 ( 3osc ) 64 2 + N ( Hz ) --- Formula (3) PWM FREQUENCY N 0 1 2 3 FOSC 100kHz 200kHz 390.6 400kHz 781.3 390.6 800kHz 1562.5 781.3 390.6 DIVIDE 00 01 10 11 NOTE) 195.3 97.7 48.8 24.4 195.3 97.7 48.8 195.3 97.7 195.3 UNIT : Hz PWM frequencies written in bold or neighbors are recommended, otherwise it might cause LED flickering. (6) LEVEL SHIFTER The level shifter allows the communication with the MPU working at the power supply voltage lower than the VDD. Apply the MPU power-supply-voltage on the VDDL terminal. The voltage range is: 1.8V TABLE 8 RESET REGISTER REV HOLD STBY BRIGHT SOFF DIVIDE PWM REGISTER1-7 DATA 0 0 0 000 0 00 000000 Default status Refer to Table 5 Sensor sampling is enabled Standby Off Luminance sensor control is enabled PWM duty 0% (LED off) (8) TEMPERATURE COMPENSATION The reference voltage (VREF) generator has temperature compensation, which suppresses the characteristic degradation of LEDs at high temperatures. Refer to "ILED vs. Temperature" shown in the "DC Electrical Characteristics". - 10 - Ver.2003-10-23 NJU6052 (9) APPLICATIONS INFORMATION (9-1) PWM DUTY and LED CURRENT The average LED current is programmed with the single resistor RLED and the PWM duty, as shown in Formula (4). I LED(avg) = I LED(max) I LED(max) = VREF RLED DUTY 100 --- Formula (4) (9-2) INDUCTOR SELECTION Formula (5) is used to choose an optimum inductor, as shown below: V 2 OUT - VIN I LED L= 2 I LIMIT f OSC --- Formula (5) : Power conversion efficiency (= 0.7 to 0.8) The power supply voltage VIN may fluctuate in battery-powered applications. For this reason, the minimum voltage should be applied to the VIN in Formula (5). The NJU6052 has about 200ns of delay time (TDELAY), which is defined as the period from the reach of the current limit 720mA to the MOS-switch-off. The TDELAY may cause an overshoot-inductor-current, which is called the peak current IL,PEAK, and calculated by Formula (6). Therefore, it is recommended that an inductor with a rating twice of the IL,PEAK and a low DCR (DC resistance) be used for high efficiency. VIN (max) - VDS TDELAY I L,PEAK = I LIMIT + L VDS VIN(MAX) --- Formula (6) : Drain-Source voltage of the MOS switch (=ILIMIT*RON) : Maximum of VIN Voltage (9-3) DIODE SELECTION A Schottky diode with a low forward-voltage-drop and a fast switching-speed is ideal. And the diode must have a rating greater than the output voltage and the output current in the system. (9-4) CAPACITOR SELECTION A low ESR (Equivalent Series Resistance) capacitor should be used at the output to minimize output ripples. A multi-layer ceramic capacitor is the best selection for the NJU6052 application because of not only the low ESR but its small package. A ceramic capacitor as the input decoupling-capacitor is also recommended and should be placed as close to the NJU6052 as possible. Ver.2003-10-23 - 11 - NJU6052 ! ABSOLUTE MAXIMUM RATINGS PARAMETERS VDD Power Supply VDDL Power Supply Input Voltage Input Voltage Switch Voltage Power Dissipation Operating Temperature Storage Temperature NOTE1) NOTE2) SYMBOL VDD VDDL VIN1 VIN2 VSW PD Topr Tstg CONDITIONS RATINGS -0.3 to +6 -0.3 to VDD -0.3 to VDD+0.3 -0.3 to VDDL+0.3 +18.0 T.B.D. (QFN28) 540 (SSOP20) -40 to +85 -55 to +125 UNIT V V V V V mW C C 3 4 5 Ta=25C NOTE CX/TCLK, REF, FB, SENS terminals REQ, DATA, SCK, RSTb Terminals SW terminal NOTE3) All voltages are relative to VSS = 0V reference. Do not exceed the absolute maximum ratings, otherwise the stress may cause a permanent damage to the IC. It is also recommended that the IC be used in the range specified in the DC electrical characteristics, or the electrical stress may cause mulfunctions and affect the reliability. The switch voltage VSW is the highest voltage in the system. This voltage must not exceed the absolute maximum rating. VSW =VF(LED) x N(LED) +VF(D1) +VREF VF(LED) N(LED) VF(D1) :Forward Voltage of LED :The Number of LEDs :Forward Voltage of Diode D1 For instance, when VF(LED) = 3.6V, N(LED)=4pcs, VF(D1)=0.3V, VREF=0.6V(TYP), VSW = 3.6V x 4 + 0.3V + 0.6V = 15.3V. NOTE4) NOTE5) Mounted on the glass epoxy board (50mm x 50mm x 1.6mm) Mounted on the board specified by EIA/JEDEC (2-layer FR-4, 76.2mm x 114.3mm x 1.6mm) - 12 - Ver.2003-10-23 NJU6052 ! DC ELECTRICAL CHARACTERISTICS VDD=3.0 to 5.5V, Ta=-40 to 85C PARAMETERS VDD Power Supply VDDL Power Supply Output Current Reference Voltage Operating Current Standby Current VSO Power Supply PWM REGISTER0 Selected Voltage PWM REGISTER1 Selected Voltage PWM REGISTER2 Selected Voltage PWM REGISTER3 Selected Voltage PWM REGISTER4 Selected Voltage PWM REGISTER5 Selected Voltage PWM REGISTER6 Selected Voltage PWM REGISTER7 Selected Voltage Input "L" Level Input "H" Level Output "L" Level Output "H" Level Oscillation Frequency Oscillation Duty Switch Current Limit Switch On Voltage Over Voltage Protection SYMBOL VDD VDDL IOUT VREF IOPR ISTBY VSO VD0 VD1 VD2 VD3 VD4 VD5 VD6 VD7 VIL VIH VOL VOH fOSC DOSC ILIMIT VDS(on) VOVP Ta=25C DC/DC Converter OFF fosc=350kHz CONDITIONS MIN. 3.0 1.8 60 0.558 0.60 1.0 2.23 SENS terminal, REV=0 SENS terminal, REV=0 SENS terminal, REV=0 SENS terminal, REV=0 SENS terminal, REV=0 SENS terminal, REV=0 SENS terminal, REV=0 SENS terminal, REV=0 SCK, DATA, REQ, RSTB terminals SCK, DATA, REQ, RSTB terminals DATA terminals VDDL=1.8V, IOL=0.4Ma DATA terminals VDDL=1.8V, IOH= - 0.04mA VDD=3V, CX=82pF VDD=3V, CX=82pF SW terminal, VDD=4.2V VFB>VREF/2, Ta=25C SW terminal, VDD=4.2V ISW=720mA, Ta=25C VOUT terminal 0 0.015VSO 0.030VSO 0.060VSO 0.110VSO 0.220VSO 0.440VSO 0.880VSO 0 0.8VDDL 2.40 0.642 1.4 1 2.57 0.0055VSO 0.0185VSO 0.040VSO 0.090VSO 0.180VSO 0.360VSO 0.720VSO VSO 0.2VDDL VDDL 0.2VDDL 0.8VDDL 245 77 610 350 82 720 1 17.5 455 87 825 1.4 RATINGS TYP. MAX. 5.5 3.6 Unit V V mA V mA uA V V V V V V V V V V V V V kHz % mA V V Note 1 2 3 4 5 6 Ver.2003-10-23 - 13 - NJU6052 NOTE1) Output Voltage Test Conditions ! TEST Command B7 0 0 ! TEST Circuit LED VDD D1 L1 C1 C2 R1 RLED fOSC B6 1 1 B5 1 0 B4 1 0 B3 1 0 B2 0 0 B1 0 0 B0 0 0 :VF=3.6V, ILED=20mA :5V :Schottky diode :6.8uH :4.7uF :1uF :100k : 30 : 350kHz / Duty 82% L1 VDD C1 VDD SW D1 A VOUT R1 CPU - 14 - VDDL C2 DATA REQ SCK RSTb SENS CX/TCLK VSS RLED FB Ver.2003-10-23 NJU6052 NOTE2) TEMPERATURE COMPENSATION The reference voltage (VREF) generator has temperature compensation, which suppresses the characteristic-degradation of LEDs at high temperatures. The VREF is regulated to 0.6V typical in the temperature range up to 45C, and gradually decreases as the ambient temperature rises in the range higher than 45C. 1.0 VREF[V] 0.5 0.0 -50 -25 0 25 50 TEMPERATURE[] 75 100 VREF VS TEMPERATURE FIGURE 4 VREF vs. TEMPERATURE 30 RLED=30 RLED=40 ILED[mA] 20 10 0 -50 -25 0 25 50 TEMPERATURE[] 75 100 ILED VSTEMPERATURE FIGURE 5 ILED vs. TEMPERATURE Ver.2003-10-23 - 15 - NJU6052 NOTE3) Operating Current Test Conditions ! TEST Command B7 0 0 NOTE4) Standby Current ! TEST Command B7 0 0 B6 * 1 B5 * 0 B4 * 0 B3 * 0 B2 B1 1 * 0 0 *: "Don't care" B0 * 0 B6 1 1 B5 1 0 B4 1 0 B3 1 0 B2 0 0 B1 0 0 B0 0 0 ! TEST Circuit (Operating Current, Standby Ciurrent) LED D1 L1 C1 C2 R1 RLED fOSC :VF=3.6V, ILED=20mA :Schottky diode :6.8uH :4.7uF :1uF :100K :30 :350kHz / Duty 82% L1 VDD C1 A VDD SW D1 VOUT R1 CPU - 16 - VDDL C2 DATA REQ SCK RSTb SENS CX/TCLK VSS FB RLED Ver.2003-10-23 NJU6052 NOTE5) VSO Power Supply Test Condition ! TEST Command B7 0 0 ! TEST Circuit LED D1 L1 C1 C2 R1 R2 RLED fOSC B6 1 1 B5 1 0 B4 1 0 B3 1 1 B2 0 0 B1 0 0 B0 0 0 :VF=3.6V, ILED=20mA :Schottky diode :6.8uH :4.7uF :1uF :100K :1K :30 : 350kHz / Duty 82% L1 VDD C1 VDD SW D1 VOUT R1 CPU V Ver.2003-10-23 VDDL C2 DATA REQ SCK RSTb SENS VSO CX/TCLK FB RLED VSS R2 - 17 - NJU6052 NOTE6) OSCILLATOR The built-in oscillator incorporates a reference power supply, so its frequency is independent from the VDD. The frequency is varied by the external capacitor CX, as shown below. fOSC vs CX 1000 900 800 700 600 500 400 300 200 100 0 0 100 200 CX(pF) 300 400 500 fOSC(kHz) Figure 7 fOSC vs. CX (Reference but not guaranteed) - 18 - Ver.2003-10-23 NJU6052 ! AC ELECTRICAL CHARACTERISTICS VDD=3.0 to 5.5V, Ta=-40 to 85C PARAMETERS SCK Clock Cycle SCK Clock Width "H" Level "L" Level SYMBOL tCCY tWSCH tWSCL tREH tDAS tDAH tD0 tRES tWREH tr tf tRSL MIN. 1.0 400 400 800 400 400 400 800 1.0 RATINGS TYP. MAX. 200 100 100 UNIT us ns ns ns ns ns ns ns ns ns ns us REQ Hold Time Data Set-Up Time Data Hold Time Output Data Delay Time CL=20pF REQ Set-Up Time REQ High Level Width REQ,SCK,DATA Rising Time REQ,SCK,DATA Falling Time RSTB Pulse Width Serial Input Timing REQ tWSCL tWSCH tRES tREH tWREH SCK tDAS tDAH tSCCY DATA B7 B6 B5 Bn B0 Serial Output Timing REQ tWSCL tWSCH tRES tREH SCK tSCCY tDO DATA B7 B6 B5 Bn B0 Reset Input Timing tRSL RSTb 0.3VDD 0.3VDD Ver.2003-10-23 - 19 - NJU6052 ! TYPICAL APPLICATION CIRCUIT L1 VDD C1 VDD VSO SW D1 VOUT C2 SENS R1 VDDL DATA REQ SCK RSTb CX/TCLK VSS TEST FB RLED - 20 - CPU REF [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. Ver.2003-10-23 |
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