st1115c Silicon Touch Technology Inc., st1115c Datasheet - Page 10

• Manufacturer Part Number: st1115c
• Description: Speed Control Double Coil Brushless Motor Driver
• Manufacturer: Silicon Touch Technology Inc.

4.Operating as a pre-driver―Refer to Figure 6.
(1) When a large fan is used, the driving current may be too large for ST1115 directly
driving the fan. In this case, ST1115 may operate as a pre-driver, as illustrated in Fig. 6.
Q1 and Q2 are PNP BJT, working as driving switches. The fan speed is controlled via
the VT terminal, which can be connected to a thermistor-resistor divider or a PWM
generator.
SP-ST1115CD-A.005
VT
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
Hall
IC
VSS
Figure 6. ST1115 operates as a pre-driver.
C1
C2
VSS
VSS
Hin
VT
CF
ST1115C
GND
VDD
VSS
Version
RD
O1
O2
R3
Analog Power
：
A.005
R1
D1
Q1
VSS
Digital Power
ST1115C/ST1115D
Q2
R4
Page
R2
：
9
RD