11
BCD Semiconductor Manufacturing Limited
Apr. 2005 Rev. 1. 1
Preliminary Datasheet
4-CHANNEL BTL MOTOR DRIVER FOR DVD
AM5954A
Application Information
1.
This IC has a built-in thermal shutdown circuit
that mutes the output current when the chip tem-
perature reachs 178oC (Typ.). The hysteresis is
set to 25oC (Typ.), so the driver circuits start up
again when the chip temperature falls to 153oC
(Typ.).
2.
The driver buffer is switched off when the supply
voltage falls below 3.5V (Typ.), and is switched
back on when the voltage reaches 3.7V (Typ.)
again.
3.
In case standby pin voltage is under 0.5V or
opened, quiescent current is muted. Standby pin
voltage should be over 2.0V for normal applica-
tion.
4.
BIAS pin (pin 27) should be pulled up more than
1.2V. In case bias pin voltage is pulled down
under 0.9V (Typ.), output current is muted.
5.
Insert the by-pass capacitor (approximately
0.1
µF) between V
CC-pin and GND-pin as near as
possible to this IC.
6.
Heat dissipation fins are attached to the GND
inside the package. Make sure to connect them to
the external GND.
Supplement: (Current-feedback driver)
The transmission gain (output current/input
voltage) is given by:
gm = 1 / (RD + RWIRE) (A/V)
RWIRE is the total gold wire resistance inside the
package (0.15
Ω ± 0.05 Ω ) (Typ.).