Optical disc ICs 4-channel BTL driver for CD players BA6198S / BA6198FP The BA6198S and BA6198FP are ICs with an internal 4-channel BTL power driver for CD players, a 5V regulator (requires attached PNP transistor), standard operational amplifier, and reset output pin. All driver channels have a gain adjustment pin, and so can be set to the desired gain. In addition, the internal level shift circuit helps reduce the number of attached components. Applications CD players, CD-ROM drives and other optical disc devices Features 1) 4-channel BTL driver on a HSOP 28-pin power package (BA6198FP), allowing for application miniaturization. 2) Gain is adjustable with an attached resistor. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 308 3) Internal thermal shutdown circuit. 4) Internal 5V regulator (requires attached PNP resistor) 5) Internal standard operational amplifier. 6) Reset output pin. Optical disc ICs BA6198S / BA6198FP Block diagram Pin descriptions 309 Optical disc ICs Input / output circuits Parentheses ( 310 BA6198S / BA6198FP ) indicate BA6198S Optical disc ICs BA6198S / BA6198FP Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 8V, f = 1kHz, RL = 8Ω) 311 Optical disc ICs Measurement circuit 312 BA6198S / BA6198FP Optical disc ICs BA6198S / BA6198FP Measurement circuit switch table 313 Optical disc ICs Application example 314 BA6198S / BA6198FP Optical disc ICs Operation notes (1) Relationship between mute and reset output Drop in regulator voltageWhen the regulator voltage drops below 4.0V (typically), the reset output changes to the low level and the IC is simultaneously muted. When the regulator voltages rises above 4.2V (typically), reset output changes to the high level and muting is released. Drop in bias voltageWhen the bias pin voltage drops below 1.4V (typically), the IC is muted and the reset output simultaneously changes to the low level. During ordinary use, the bias voltage should be kept above 1.6V. BA6198S / BA6198FP Thermal shutdownWhen the chip temperature rises above 175C (typically), the IC is muted and the reset output simultaneously changes to the low level. MutingWhen the mute pin voltage is opened or lowered below 0.5V, the IC is muted, but the reset output remains the same. (2) Muting occurs during thermal shutdown, mute-on operations or a drop in the bias pin voltage or regulator voltage. In each case, only the drivers are muted. During muting, the output pins remain at the internal bias voltage, roughly (VCC-VF) / 2. (3) Be sure to connect the IC to a 0.1µF bypass capacitor between the power supplies, at the base of the IC. (4) The radiating fin is connected to the package’s internal GND, but should also be connected to an external ground. (5) The capacitor between regulator output (pin 8) and GND also serves to prevent oscillation of the IC, so select one with good temperature characteristics. Electrical characteristic curves 315 Optical disc ICs 316 BA6198S / BA6198FP Optical disc ICs BA6198S / BA6198FP External dimensions (Units: mm) 317