BA5995FM

Optical disc ICs

7/8

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Operation notes

(1) Thermal shut down circuit is built in. In case IC chip temperature rises to 175

°C(typ.), thermal shut down circuit

operates and muted the output current. Next time IC chip temperature falls below 150

°C(typ.), the driver blocks start.

(2) Bias pin (pin1) should be pulled up more than 1.3V. In case bias pin voltage is under 0.7V(typ.), output current is

muted.

(3) In case supply voltage falls below 3.8V(typ.), output current is muted. Next time supply voltage rises to 4.0V (typ.), the

driver blocks start.

(4) Mute operation is caused by thermal shut down, decrease of bias pin voltage or decrease of supply voltage.

When mute is done, output voltage becomes internal reference voltage (about PowVcc/2).

(5) In case of one of the standby terminals turn into or open , correspondence channel circuit (include opamps) is muted.

(6) Both of the standby terminals low or open, all circuits shutdown (sleep mode) and all output pins become high

impedance. In addition to threshold is 1.4V(typ.).

(8) Take care the external resistor value of OPamp .

OPamp source current supplies to internal resistor (10K

Ω) as well as external resistor.

µF).

(10) Keep the GND pin voltage the lowest of all pins .

(11) Heat dissipation fins are attached to the GND on the inside of the package. Make sure to connect these to the

external GND.

(12) If the mute pin (pin6) voltage rises above 2.0V, the output (CH1) current can be muted.

Under normal operating conditions, make sure to open pin7 or pull it down below 0.5V.

Next figure is high impedance mute timing chart.

2V

MUTE

(Pin6)

0V

t

tm

t

(Pin14-Pin13)

0V

0.5mV

BIAS=1.65V

Ω

tm

≤125µsec