View MXD1810_45413.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-2243; Rev 0; 10/01
Low-Power P Reset Circuits in 3-Pin SC70/SOT23
General Description
The MXD1810-MXD1813/MXD1815-MXD1818 family of microprocessor (P) reset circuits monitor power supplies in P and digital systems. These devices provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +2.5V/+3.0V/+3.3V (MXD1815-MXD1818), and +5V (MXD1810-MXD1813) systems. These circuits assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping reset asserted for at least 100ms after VCC rises above the reset threshold. The MXD1813/ MXD1818 also keep reset asserted for at least 100ms after the output is momentarily pulled to GND by an external push-button switch. The MXD1812/MXD1817 have an active-high push-pull RESET output. The MXD1810/MXD1815 (push-pull) and MXD1811/MXD1813/MXD1816/MD1818 (open-drain) have an active-low RESET output. The open-drain devices (MXD1811/MXD1813/MXD1816/MXD1818) have an internal pullup resistor to V CC . The MXD1813/MXD1818 feature a debounced manual reset feature that asserts a reset if the RESET pin is pulled low for more than 1.5s. When used to initiate manual reset, RESET debounces signals from devices such as mechanical switches. For devices with this feature, the release of the external switch triggers the reset period. The MXD1810-MXD1813/MXD1815-MXD1818 are guaranteed to output the correct logic state for VCC down to +1V. These ICs provide a reset comparator designed to ignore fast transients on V CC . Reset thresholds are available between +2.18V and +4.62V. These small, low-power (4A) devices are ideal for use in portable equipment. All are available in space-saving 3-pin SC70 and SOT23 packages, and are specified from -40C to +105C.
Features
o Precision Monitoring of +2.5V, +3V, +3.3V, and +5V Power-Supply Voltages o Available in Four Reset Output Configurations o Factory-Set Reset Threshold Voltages: 2.18V, 2.31V, 2.55V, 2.88V, 3.06V, 4.12V, 4.37V, 4.62V o 2.5% Reset Threshold Accuracy Over Temperature o Fixed Reset Timeout Period: 100ms (min) o Guaranteed RESET/RESET Valid to VCC = +1V o Debounced Manual Reset Detect (MXD1813/MXD1818) o Power-Supply Transient Immunity o No External Components o Low Power Consumption (4A) o Pin Compatible with DS181_ Products (SOT23) o 3-Pin SC70 and SOT23 Packages
MXD1810-MXD1813/MXD1815-MXD1818*
Ordering Information
PART MXD1810UR_ _-T MXD1810XR_ _-T
The
TEMP. RANGE -40oC to +105oC -40oC to +105oC
PIN-PACKAGE 3 SOT23-3 3 SC70-3
MXD1810-MXD1813/MXD1815-MXD1818 are available with factory-set VCC reset thresholds from +2.18V to +3.06V (MXD1815-MXD1818) and +4.12V to +4.62V (MXD1810- MXD1813). Choose the desired reset-threshold suffix from the Reset Threshold Table and insert it in place of the "_ _" following "R" in the part number. All devices are available in tapeand-reel only in 2500 unit increments. Other threshold voltages may be available. Contact factory for availability. Ordering Information continued at end of data sheet.
Applications
Computers and Controllers Intelligent Instruments Set-Top Boxes Printers Automotive Systems Critical P and C Monitoring Portable/Battery-Powered Equipment
*Patent pending
MXD181_X
RESET 2 (RESET)
Pin Configurations
TOP VIEW
VCC 1 3 GND VCC 2 RESET 1 (RESET)
MXD181_U
3
GND
SC70-3
SOT23-3
() ARE FOR THE MXD1812/MXD1817
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
Low-Power P Reset Circuits in 3-Pin SC70/SOT23 MXD1810-MXD1813/MXD1815-MXD1818
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................-0.3V to +6.0V Push-Pull RESET (MXD1810/MXD1815), RESET (MXD1812/MXD1817) to GND.....-0.3V to (VCC + 0.3V) Open-Drain RESET (MXD1811/MXD1816) to GND................................................................-0.3V to +6.0V Open-Drain RESET (MXD1813/MXD1818) to GND ....................................................-0.3V to (VCC + 0.3V) Input Current (VCC, RESET) ................................................20mA Output Current (RESET, RESET).........................................20mA Continuous Power Dissipation (TA = +70C) 3-Pin SC70 (derate 2.17mW above +70C) ..................174mW 3-Pin SOT23 (derate 4mW/C above +70C) ...............320mW Operating Temperature Range .........................-40C to +105C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = full range, TA = -40C to +105C, unless otherwise specified. Typical values are at TA = +25C.) (Note 1)
PARAMETER Supply Voltage Range Supply Current SYMBOL VCC ICC CONDITIONS TA = 0C to +105C TA = -40C to +105C VCC = +5.5V, VCC > VTH, no load VCC = +3.6V, VCC > VTH, no load MXD181_ _ R46 MXD181_ _ R44 MXD181_ _ R41 Reset Threshold VTH MXD181_ _ R31 MXD181_ _ R29 MXD181_ _ R26 MXD181_ _ R23 MXD181_ _ R22 Active Reset Timeout Period VCC to Reset Delay Push-Button Detect to Reset Push-Button Reset Timeout Period Input Low Voltage Input High Voltage RESET Output Source Current RESET Output Source Current tRP tRD tPB tPBRST VIL VIH IOH IOH VCC rising VCC = (VTH + 100mV) falling to (VTH - 200mV) VCC rising, tR = 5s MXD1813/MXD1818 only MXD1813/MXD1818 only MXD1813/MXD1818 only TA = +25C to +105C TA = -40C to +25C 0.7 x VCC 350 350 100 1.5 100 150 250 0.34 0.15 4.50 4.25 4.00 2.98 2.80 2.47 2.25 2.12 100 MIN 1.0 1.2 9 4 4.62 4.37 4.12 3.06 2.88 2.55 2.31 2.18 150 2 150 TYP MAX 5.5 5.5 16 10 4.75 4.49 4.24 3.15 2.97 2.64 2.37 2.25 250 5 250 ms s ms s ms V V A A V UNITS V A
MXD1813/MXD1818 only VCC VTH(MAX), reset not asserted, MXD1810/MXD1815 VCC VTH(MIN), reset asserted, MXD1812/MXD1817 VCC 2.7V, reset asserted, VOUT = 0.4V MXD1810/MXD1811/MXD1813/MXD1815/ MXD1816/MXD1818 (Note 2) VCC 2.7V, reset not asserted, , VOUT = 0.4V MXD1812/MXD1817
RESET Output Sink Current
IOL
10
mA
RESET Output Sink Current
IOL
10
mA
2
_______________________________________________________________________________________
Low-Power P Reset Circuits in 3-Pin SC70/SOT23
ELECTRICAL CHARACTERISTICS (continued)
(VCC = full range, TA = -40C to +105C, unless otherwise specified. Typical values are at TA = +25C.) (Note 1)
PARAMETER Output High Voltage Output Capacitance (Note 2) Internal Pullup Resistor Open-Drain SYMBOL VOH COUT RP MXD1811/MXD1816 MXD1813/MXD1818 3.5 3.1 5.5 5.5 CONDITIONS 0 < IOH < 500A MIN VCC 0.5 TYP VCC 0.1 10 7.5 7.5 MAX UNITS V pF k
MXD1810-MXD1813/MXD1815-MXD1818
Note 1: Production testing done at TA = +25C; limits over temperature guaranteed by design. Note 2: The MXD1811/MXD1813/MXD1816/MXD1818 have an internal pullup resistor which may deliver 1mA of sink current. Note 3: Guaranteed by design.
Typical Operating Characteristics
(TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
MXD1810-13/15-18 toc01
RESET TIMEOUT PERIOD vs. TEMPERATURE (VCC RISING)
MXD1810-13/15-18 toc02
NORMALIZED RESET THRESHOLD vs. TEMPERATURE (VCC FALLING)
MXD1810-13/15-18 toc03
10 RESET/RESET NOT ASSERTED 8 SUPPLY CURRENT (A) VCC = +5V
1.010 NORMALIZED RESET THRESHOLD
160 TIMEOUT PERIOD (ms) 156 152 148 144 140 VCC = +2.5V
VCC = +5V
1.005 VTH = +4.62V 1.000 VTH = +2.18V 0.995
6
4 VCC = +3.3V 2 VCC = +2.5V
0 -40 -10 20 50 80 110 TEMPERATURE (C)
0.990 -40 -10 20 50 80 110 -40 -10 20 50 80 110 TEMPERATURE (C) TEMPERATURE (C)
POWER-DOWN RESET DELAY vs. TEMPERATURE
MXD1810-13/15-18 toc04
MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE
MXD1810-13/15 toc05
OUTPUT VOLTAGE vs. OUTPUT SINK CURRENT
MXD1810-13/15-18 toc06
3.0 POWER-DOWN RESET DELAY (s) 2.5 VTH = +4.62V 2.0 1.5 1.0 0.5 0 -40 -10 20 50 80 110 TEMPERATURE (C)
100 MAXIMUM TRANSIENT DURATION (s) 90 80 70 60 50 40 30 20 10 0 RESET OCCURS ABOVE THIS LINE
200
160 OUTPUT VOLTAGE (mV)
120
80
VTH = +2.18V
40
0 10 100 1000 RESET THRESHOLD OVERDRIVE, VTH - VCC (mV) 0 3 6 9 12 15 OUTPUT CURRENT (mA)
_______________________________________________________________________________________
3
Low-Power P Reset Circuits in 3-Pin SC70/SOT23 MXD1810-MXD1813/MXD1815-MXD1818
Typical Operating Characteristics (continued)
(TA = +25C, unless otherwise noted.)
OUTPUT VOLTAGE vs. OUTPUT SOURCE CURRENT
MXD1810-13/15-18 toc07
INPUT LOW VOLTAGE vs. VCC AND TEMPERATURE
MXD1810-13/15 toc08
0.5
0.8
INPUT LOW VOLTAGE (V)
0.4 VCC - VOUT (V)
VCC = +5.5V 0.6
0.3
0.2
0.4 VCC = +2.2V
0.1
0 0 0.5 1.0 1.5 2.0 2.5 3.0 OUTPUT CURRENT (mA)
0.2 -40 -10 20 50 80 110 TEMPERATURE (C)
Pin Descriptions
MXD1810/MXD1815
PIN SC70 2 1 3 SOT23 1 2 3 RESET VCC GND Push-Pull, Active-Low Reset Output. RESET changes from high to low when VCC drops below the selected reset threshold. RESET remains low for the reset timeout period after VCC exceeds the device reset threshold. Supply Voltage and Input for Reset Threshold Monitor Ground NAME FUNCTION
MXD1811/MXD1816
PIN SC70 2 1 3 SOT23 1 2 3 NAME FUNCTION Open-Drain, Active-Low Reset Output. RESET changes from high to low when VCC drops below the selected reset threshold. RESET remains low for the reset timeout period after VCC exceeds the device reset threshold. RESET has an internal 5.5k pullup resistor. Supply Voltage and Input for Reset Threshold Monitor Ground
RESET VCC GND
4
_______________________________________________________________________________________
Low-Power P Reset Circuits in 3-Pin SC70/SOT23
Pin Descriptions (continued)
MXD1812/MXD1817
PIN SC70 2 1 3 SOT23 1 2 3 NAME FUNCTION Push-Pull, Active-High Reset Output. RESET changes from low to high when VCC drops below the selected reset threshold. RESET remains high for the reset timeout period after VCC exceeds the device reset threshold. Supply Voltage and Input for Reset Threshold Monitor Ground
MXD1810-MXD1813/MXD1815-MXD1818
RESET VCC GND
MXD1813/MXD1818
PIN SC70 SOT23 NAME FUNCTION Open-Drain, Active-Low Reset Output with Manual Reset Detect. RESET changes from high to low when VCC drops below the selected reset threshold, or RESET is externally pulled low for at least 1.5s. RESET remains low for the reset timeout period after VCC exceeds the device reset threshold or after the external manual reset is released. RESET has an internal 5.5k pullup resistor. Supply Voltage and Input for Reset Threshold Monitor Ground
2
1
RESET
1 3
2 3
VCC GND
Detailed Description
RESET/RESET Output
A microprocessor's (P's) reset input starts the microprocessor in a known state. The MXD1810-MXD1813/ MXD1815-MXD1818 P supervisory circuits assert reset to prevent code-execution errors during powerup, power-down, and brownout conditions (Figure 4). Whenever VCC falls below the reset threshold, the reset output asserts. Once VCC exceeds the reset threshold, an internal timer keeps the reset output asserted for the specified reset timeout period (tRP). Reset is also triggered by an externally initiated rising edge on the RESET pin (MXD1813/MXD1818), following a low signal of 1.5s minimum duration.
(tPBRST). A manual reset input shorter than 1.5s may release RESET without the 100ms minimum reset timeout delay. To facilitate use with mechanical switches, the MXD1813/MXD1818 contain internal debouncing circuitry. A debounced waveform is shown in Figure 6.
Applications Information
Interfacing to Ps with Bidirectional Reset Pins
Since the RESET output on the MXD1811/MXD1816 is open drain, these devices interface easily with Ps that have bidirectional reset pins, such as the Motorola 68HC11. Connecting the P supervisor's RESET output directly to the microcontroller's (C's) RESET pin allows either device to assert reset (Figure 7). No external pullup resistor is required, as it is contained within the MXD1811/MXD1816.
Push-Button Reset (MXD1813/MXD1818)
Many P-based products require push-button reset capability (Figure 5), allowing the operator, a test technician, or external logic circuitry to initiate reset. On the MXD1813/MXD1818, a logic-low on RESET held for greater than 1.5s asserts a reset. RESET deasserts following a 100ms minimum reset timeout delay
Negative-Going VCC Transients In addition to issuing a reset to the P during power-up, power-down, and brownout conditions, these devices are relatively immune to short-duration, negative-going VCC transients (glitches).
5
_______________________________________________________________________________________
Low-Power P Reset Circuits in 3-Pin SC70/SOT23 MXD1810-MXD1813/MXD1815-MXD1818
Functional Diagram
MXD1810 MXD1812 MXD1815 MXD1817 VCC
MXD1811 MXD1816 VCC
RESET RESET GENERATOR
RESET GENERATOR
RESET OR RESET
VREF
VREF
Figure 1. Functional Diagram, Push-Pull Output
Figure 2. Functional Diagram, Open-Drain Active-Low Output
MXD1813 MXD1818 VCC
The Typical Operating Characteristics show the Maximum Transient Duration vs. Reset Threshold Overdrive for which reset pulses are not generated. The graph shows the maximum pulse width that a negativegoing VCC transient may typically have without issuing a reset signal. As the amplitude of the transient increases, the maximum allowable pulse width decreases.
MR MONITOR
Ensuring a Valid Reset Output Down to VCC = 0
RESET
RESET GENERATOR
VREF
Figure 3. Functional Diagram, Open-Drain Active-Low Output with Manual Reset Detection
When VCC falls below the minimum operating voltage, push-pull structured reset sinking (or sourcing) capabilities decrease dramatically. High-impedance CMOSlogic inputs connected to the RESET/RESET pin can drift to indeterminate voltages. This does not present a problem in most cases, since most Ps and circuitry do not operate at V CC below +1V. For MXD1810/ MXD1815 applications where RESET must be valid down to VCC = 0, adding a pulldown resistor between RESET and GND removes stray leakage currents, holding RESET low (Figure 8). The pulldown resistor value is not critical; 100k is large enough not to load RESET and small enough to pull RESET low. For MXD1812/
6
_______________________________________________________________________________________
Low-Power P Reset Circuits in 3-Pin SC70/SOT23 MXD1810-MXD1813/MXD1815-MXD1818
VCC
VTH VCC MXD1813 MXD1818 tRP VCC(MIN) RESET
VCC
RESET RESET
GND RESET tRP
MANUAL RESET
Figure 4. Power-Up Reset Timing Diagram
Figure 5. Push-Button Manual Reset
VCC tPBRST (OPEN) SWITCH BOUNCE EXTERNAL PUSH BUTTON (CLOSED) tPBRST
RESET
Figure 6. Manual Reset Timing Diagram
MXD1817 applications where RESET must be valid to VCC = 0, a 100k pullup resistor between RESET and VCC holds RESET high when VCC falls below the minimum operating voltage (Figure 9). The MXD1811/MXD1813/MXD1816/MXD1818 have open-drain, active-low outputs with a pullup resistor included internal to the devices. While using these devices RESET will most likely not maintain an active
condition when the supply voltage drops below the minimum VCC, but will drift to a nonactive level due to the pullup resistor and the reduced sinking capability of the open-drain output. Therefore, these devices are not recommended for applications where the RESET pin is required to be valid at VCC = 0.
_______________________________________________________________________________________
7
Low-Power P Reset Circuits in 3-Pin SC70/SOT23 MXD1810-MXD1813/MXD1815-MXD1818
VCC
Table 1. Device Marking Codes
PART
VCC VCC MXD1811 MXD1816 P RESET RESET GND GND
TOP MARK SOT23 FZIV FZKD FZKC FZKF FZIW FZKE FZKH FZKG FZIX FZIY FZKJ FZKI FZKN FZIZ FZKM FZKL FZKK FZKR FZKQ FZKP FZKO FZJA FZJB FZKV FZKU FZKT FZKS FZKY FZKX FZJC FZKW FZJE SC70 AEK AHU AHT AHW AEL AHV AHY AHX AEM AEN AIA AHZ AIE AEO AID AIC AIB AII AIH AIG AIF AEP AEQ AIM AIL AIK AIJ AIP AIO AER AIN AEV
MXD1810_R46 MXD1810_R44 MXD1810_R41 MXD1811_R46 MXD1811_R44 MXD1811_R41 MXD1812_R46 MXD1812_R44 MXD1812_R41
Figure 7. Interfacing to Microprocessors with Bidirectional Reset Pins
VCC
MXD1813_R46 MXD1813_R44 MXD1813_R41 MXD1815_R31 MXD1815_R29
VCC VCC MXD1810 MXD1815 P RESET RPULLDOWN* GND RESET GND
MXD1815_R26 MXD1815_R23 MXD1815_R22 MXD1816_R31 MXD1816_R29 MXD1816_R26 MXD1816_R23 MXD1816_R22
*MXD1810/MXD1815 ONLY
MXD1817_R31 MXD1817_R29 MXD1817_R26 MXD1817_R23 MXD1817_R22 MXD1818_R31
Figure 8. Ensuring Valid RESET Output Down to VCC = 0 (MXD1810/MXD1815 only)
VCC
VCC RPULLUP* VCC P GND GND
MXD1818_R29 MXD1818_R26 MXD1818_R23 MXD1818_R22
MXD1812 MXD1817
RESET
RESET
*MXD1812/MXD1817 ONLY
Figure 9. Ensuring Valid RESET Output Down to VCC = 0 (MXD1812/MXD1817 only) 8 _______________________________________________________________________________________
Low-Power P Reset Circuits in 3-Pin SC70/SOT23
Selector Guide
OPEN-DRAIN RESET WITH PUSHBUTTON DETECT -- -- -- -- -- --
MXD1810-MXD1813/MXD1815-MXD1818
PART
5V SYSTEMS
2.5V/3.0V/3.3V SYSTEMS -- -- -- --
PUSH-PULL RESET -- -- -- -- -- --
OPEN-DRAIN RESET -- -- -- -- -- --
PUSH-PULL RESET -- -- -- -- -- --
MXD1810 MXD1811 MXD1812 MXD1813 MXD1815 MXD1816 MXD1817 MXD1818
-- -- -- --
Ordering Information (continued)
PART MXD1811UR_ _-T MXD1811XR_ _-T MXD1812UR_ _-T MXD1812XR_ _-T MXD1813UR_ _-T MXD1813XR_ _-T MXD1815UR_ _-T MXD1815XR_ _-T MXD1816UR_ _-T MXD1816XR_ _-T MXD1817UR_ _-T MXD1817XR_ _-T MXD1818UR_ _-T MXD1818XR_ _-T TEMP. RANGE -40 C to +105 C -40oC to +105oC -40oC to +105oC -40 C to +105 C -40 C to +105 C -40 C to +105 C -40 C to +105 C -40 C to +105 C -40 C to +105 C -40 C to +105 C -40oC to +105oC -40oC to +105oC -40 C to +105 C -40oC to +105oC
o o o o o o o o o o o o o o o o o o
Reset Threshold Table
PART MXD1810-MXD1813 MXD1810-MXD1813 MXD1810-MXD1813 MXD1815-MXD1818 MXD1815-MXD1818 MXD1815-MXD1818 MXD1815-MXD1818 MXD1815-MXD1818 SUFFIX (_ _) 46 44 41 31 29 26 23 22 TYP. RESET THRESHOLD (V) * 4.62 4.37 4.12 3.06 2.88 2.55 2.31 2.18
PIN-PACKAGE 3 SOT23-3 3 SC70-3 3 SOT23-3 3 SC70-3 3 SOT23-3 3 SC70-3 3 SOT23-3 3 SC70-3 3 SOT23-3 3 SC70-3 3 SOT23-3 3 SC70-3 3 SOT23-3 3 SC70-3
*Factory-trimmed reset thresholds are nominally 1.5% at room temperature.
The MXD1810-MXD1813/MXD1815-MXD1818 are available with factory-set VCC reset thresholds from +2.18V to +3.06V (MXD1815-MXD1818) and +4.12V to +4.62V (MXD1810- MXD1813). Choose the desired reset-threshold suffix from the Reset Threshold Table and insert it in place of the "_ _" following "R" in the part number. All devices are available in tapeand-reel only in 2500 unit increments. Other threshold voltages may be available. Contact factory for availability.
Chip Information
TRANSISTOR COUNT: 709 PROCESS TECHNOLOGY: BiCMOS
_______________________________________________________________________________________
9
Low-Power P Reset Circuits in 3-Pin SC70/SOT23 MXD1810-MXD1813/MXD1815-MXD1818
Package Information
SC70, 3L.EPS
10
______________________________________________________________________________________
Low-Power P Reset Circuits in 3-Pin SC70/SOT23
Package Information (continued)
SOTPO3L.EPS
MXD1810-MXD1813/MXD1815-MXD1818
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

▲Up To Search▲

Price & Availability of MXD1810

	To Download MXD1810 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .