Diodes AM4967 - Manual (Page 3)

3
BCD Semiconductor Manufacturing Limited
ADJUSTABLE-SPEED SINGLE-PHASE FULL-WAVE PRE-DRIVER FOR MOTOR AM4967
Oct. 2008 Rev. 1. 2
Data Sheet
Pin Number Pin Name Function
1 OUT2
Second channel P-type driver output. Open-drain output, must be connected
with pull-up resistor to drive external power devices in operation
2 OUT2B
Second channel N-type driver output. Push-pull output to drive external
power devices
3 VCC Power supply
4 CS
Current limiter indicator. Fixed to 0.2V internally. Maximum allowable cur-
rent is decided by external sample resistance. When the voltage of this pin
exceeds 0.2V, the output will be shut down by current limit. If this function is
not used, connect this pin to ground directly
5 VMIN
Minimum speed setting terminal. Connect it to VREF when disused. In case it
is tied to other power supply for controlling, an isolated resistor is necessary
6 VPWM
Speed control terminal. It is full speed mode when connected to ground. If the
speed is controlled by PWM mode, the frequency of control signal is 20kHz
to 100kHz. Moreover, a low pass network is necessary to transfer PWM to
DC level
7 COSC
PWM basic oscillation frequency generator when connected with a capacitor
of 220pF. 30kHz frequency is available.
8 FG/RD
"FG" means pin 8 is an output pin of FG signal which is used for detecting
rotation speed. "RD" means pin 8 is an output pin of RD signal, and is used
for detecting fan rotate-stop state. "FG" and "RD" can be selected according
to the requirement. This pin need to be connected with pull-up resistor when
used. A new pulse will be generated once input signal changed. Keep this pin
open when it is not to be used
9 HIN-
Hall sensor negative input. To prevent noise, this pin is recommended to be
placed as close as possible to Hall circuit. If necessary, a capacitor may be
added between HIN+ and HIN- to reduce the influence caused by noise
10 HIN+
Hall sensor positive input. To avoid noise, this pin is recommended to be
placed as close as possible to Hall circuit
11 CT
Lock protection and auto start frequency generator. It is connected with an
external 0.47
µF capacitor which decides lock-rotate time and start time. If
lock-rotate protection function is disused, please connect this pin to GND
12 LS
Linear start terminal. This pin is connected to VREF externally via a capacitor
of 0.47
µF to 1µF which enables fan start steadily. Start time is dependent to
the capacitance. If linear start function is not used, connect this pin to ground
13 VREF 5V voltage reference
14 GND Ground for circuit control
15 OUT1B
First channel N-type driver output. Push-pull output to drive external power
devices
16 OUT1
First channel P-type driver output. Open-drain output, must be connected with
pull-up resistor to drive external power devices in operation
Pin Description