View BA6810_167308.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Audio ICs
Fluorescent display tube level meter driver, 12-point 2 channel, VU scale, bar display
BA6810F
The BA6810F is a two-channel, 12-point fluorescent display tube driver for VU-scale bar-level meters. It uses a dynamic-drive system and has both AC and DC inputs. The AC input mode has a peak hold circuit. The IC features a power-on mute, and the output block can directly drive fluorescent display tubes, so few external components are required, allowing cost and space savings while improving reliability. The grid output duty cycle is 1 / 8. FApplications Level meters for all types of AV equipment FFeatures 1) Uses dynamic-drive system to display two 12-point channels. 28-pin SOP package. 2) AC and DC inputs provided. Switching function allows two-mode display. 3) Upper 8 points have peak hold function in AC mode (two seconds typ.). 4) Power-on mute function.
5) Forced-mute function. 6) Terminal for meter sensitivity adjustment provided (adjustment with one terminal is possible). 7) I2L injector current terminal provided. 8) Square root compression amplifier built in. 9) Dynamic-drive system reduces the power dissipation of the fluorescent display tube power supply.
FBlock diagram
790
Audio ICs
FAbsolute maximum ratings (Ta = 25_C)
BA6810F
FRecommended operating conditions
791
Audio ICs
FElectrical characteristics (unless otherwise noted, Ta = 25_C and VCC = 5.0V)
BA6810F
792
Audio ICs
BA6810F
793
Audio ICs
FMeasurement circuit
BA6810F
FApplication example
794
Audio ICs
FCircuit operation (1) Input block The AC input pins are pins 23 and 25, and the DC input pins are pins 27 and 28. Pin 2 is used to switch between the AC and DC inputs. When the input to pin 2 is "H", AC input is selected (pins 23 and 25). Therefore, by using pin 2 to switch between the AC and DC modes, the IC can do two jobs, using one fluorescent tube. For example, pins 23 and 25 can be used for audio signal input, and pins 27 and 28 can be used as the input for the signal meter output from a tuner (DC). (2) Peak hold circuit The BA6810F features a peak hold circuit that temporarily holds peak signal levels in AC input mode. The peak hold function can be used with the upper 8 points (5 to 12). The peak hold time depends on the oscillator frequency. It is 2 sec. (typ.) for an oscillator frequency of 2kHz. (3) MUTE function The display can be turned off by driving the MUTE terminal "H". (4) Meter sensitivity adjustment terminal Connect a potentiometer of about 10k, and adjust it so that the 8th point lights when the for an AC input of 400mVrms. The dispersion between left and right channels is "1.0dB.
BA6810F
(7) Grid and segment output timing chart. The grid and segment output timing is shown in Fig. 6.
(5) Grid output The pin 6 and 7 grid outputs are open-collector NPN transistors. The logic is active low (the fluorescent tube lights when the output is "L"), so connect two PNP transistors Q1 and Q2 as shown in the application example circuit to drive the fluorescent tubes (see Fig. 4). (6) Segment output block Pins 8 to 19 are the segment outputs. The output circuits are open-collector PNP transistors. When grid 1 is "L", the ch1 level is output (pin 23 or 27 input level), and when grid 2 is "L", the ch2 level is output (pin 25 or 28 input level). Refer to Fig. 5.
(8) Attack and recovery times The output response characteristic for AC input signals is set by pins 24 and 26. The comparator level may change somewhat due to the sag of the CR circuit discharge. (9) Oscillator frequency The resistor and capacitor connected to pin 21 determine the oscillator frequency. The oscillator frequency (fosc) and grid output period (T) are related as follows:
795
Audio ICs
FElectrical characteristics curves
BA6810F
FExternal dimensions (Units: mm)
796

▲Up To Search▲

Price & Availability of BA6810

	To Download BA6810 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .