Optical disc ICs 5-channel BTL driver for CD players BA6796FP The BA6796FP, an IC designed for CD and MD players, has a 5-channel BTL power driver and a standard operational amplifier. The spindle and tray driver share a single output buffer, and are specified with a control pin. In addition, the internal level shift circuit reduces the number of attached components. Applications CD players, CD-ROM drives, MD players and other optical disc devices Features 1) 5-channel BTL driver in a 28-pin HSOP package, allowing for application miniaturization. 2) The five drivers are turned on and off according to control pin logic combinations. 3) The tray driver operates even when the servo power supply drops. 4) Internal thermal shutdown circuit. 5) Gain is adjustable with an attached resistor. 6) Internal standard operational amplifier. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 483 Optical disc ICs Block diagram 484 BA6796FP Optical disc ICs BA6796FP Pin descriptions 485 Optical disc ICs Input / output circuits 486 BA6796FP Optical disc ICs BA6796FP Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 8V, f = 1kHz, RL = 8Ω) 487 Optical disc ICs Measurement circuit 488 BA6796FP Optical disc ICs BA6796FP Measruement circuit switch table 489 Optical disc ICs Function description CTL and CTL2 F and R (channel 5 control enabled only when channel 5 is on) 490 BA6796FP Optical disc ICs BA6796FP Application example 491 Optical disc ICs BA6796FP Operation notes (1) Setting the tray motor driver voltage (forward mode) (2) Mute functions Thermal shutdown The output current is muted when the chip temperature exceeds 175C (typically). Supply voltage drop muting The internal circuits turn off when the supply voltage drops below 4.3V (typically), and turn on again when it rises above 4.5V (typically). Electrical characteristic curves 492 Bias drop muting Muting also occurs when the bias pin voltage (26 pin) is lowered below 1.4V (typically). Be sure the voltage stays between 1.6V and 6.5V during normal operation. (3) Muting occurs during thermal shutdown and when the supply voltage or bias pin voltage drops. In each case, only the driver is muted. The output pin voltage during muting is the internal bias voltage, roughly VCC– VF / 2. (4) Attach a 0.1µF bypass capacitor to the power supply, at the base of the IC. (5) Connect the radiating fin to an external ground. Optical disc ICs BA6796FP External dimensions (Units: mm) 493