Preliminary Datasheet
ADJUSTABLE-SPEED SINGLE-PHASE FULL-WAVE PRE-DRIVER FOR MOTOR
AM4967
Pin Description
Pin Number
1
2
3
Pin Name
OUT2
OUT2B
VCC
Function
Second channel P-type driver output. Open-drain output, must be connected
with pull-up resistor to drive external power devices in operation
Second channel N-type driver output. Push-pull output to drive external
power devices
Power supply
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
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
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
PWM basic oscillation frequency generator when connected with a capacitor
of 220pF. 30kHz frequency is available.
"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
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
Hall sensor positive input. To avoid noise, this pin is recommended to be
placed as close as possible to Hall circuit
Lock protection and auto start frequency generator. It is connected with an
external 0.47µF capacitor which decides lock-rotate time and start time. If
lock-rotate protection function is disused, please connect this pin to GND
Linear start terminal. This pin is connected to VREF externally via a capacitor
of 0.47µF 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
5V voltage reference
Ground for circuit control
First channel N-type driver output. Push-pull output to drive external power
devices
First channel P-type driver output. Open-drain output, must be connected with
pull-up resistor to drive external power devices in operation
4
CS
5
VMIN
6
VPWM
7
COSC
8
FG/RD
9
HIN-
10
HIN+
11
CT
12
13
14
15
16
LS
VREF
GND
OUT1B
OUT1
Jun. 2008 Rev. 1. 1
3
BCD Semiconductor Manufacturing Limited
BCDSEMI [ BCD SEMICONDUCTOR MANUFACTURING LIMITED ]
