HV9608
Initial Release
Active Clamp Current-Mode PWM Controller
Features
Peak current-mode PWM Controller
Two complementary MOSFET drivers
Programmable deadtime between drivers
High current gate drivers for main and auxiliary outputs
Internal high voltage (12V to 250V) start-up regulator
Programmable V
IN
undervoltage lockout and hysteresis
V
DD
supply operation from 7.8V to 12V
Fixed frequency PWM operation from 25KHz to 800KHz
>50% duty cycle operation (up to 95%)
Programmable slope compensation
Programmable max duty-cycle/volt-second clamp
Capacitor programmable soft-start
Cycle-by-cycle current limiting
100ns current sense leading edge blanking
2 MHz error amplifier
Description
The HV9608 provides a single chip, optimized peak current
mode control solution for design of high performance PWM
converters using the active-clamp transformer flux reset.
Due to its programmable slope compensation feature, the
HV9608 allows operation beyond 50% duty cycle. Zero-
voltage switching can be accomplished through using the
programmable deadtime timers. The switching frequency
can be programmed from 25kHz to 800kHz using a single
resistor. The internal high voltage startup circuit can ensure
start-up from the input voltage from 12V to 250V. It can also
maintain the HV9608 in operation when the external
“bootstrap” power supply is not available. The startup
regulator is disconnected as soon as the HV9608 becomes
powered from the bootstrap winding. The HV9608 offers a
programmable soft start feature using a single external
capacitor. The cycle by cycle current limit feature can
protect the converter from overheating and damage by
limiting the output over current. The HV9608 will maintain
the cycle-by-cycle current limiting mode for a period of time
programmed by the soft start capacitor value. The HV9608
includes a single pin UVLO circuit that allows independent
accurate setting of both the turn-on and the turn-off
threshold voltage. A programmable volt-second clamp
reduces voltage stress of the switching devices. The
HV9608 is available in a space-saving TSSOP-16 package.
Applications
Networking
Telecommunication Systems and Terminals
IEEE 802.3af PoE PD Devices
SANS, Servers & Workstations
High Efficiency Instrumentation Supplies
High Efficiency Supplies for Portable Equipment
Typical Application Circuit
VIN
L
F
C
IN
1
Vo
+
T
1
HV9608
VIN
VDD
16
VDD
C
2
R
3
R1
R2
2
UVLO
DT1
Q
4
15
R
VS
R
DT1
C1
3
Q
1
C
F
REF
AGATE
14
C
SS
4
R
4
SS
GATE
13
Q
3
R
DT2
-
R
S
R
SC1
5
SC
DT2
12
R
T
6
RT
GND
11
C
3
R
SC2
7
VS
CS
10
Q
2
8
COMP
FB
9
C
4
C
Z
C
P
R
P
A122104
Supertex, Inc.
•
1235 Bordeaux Drive, Sunnyvale, CA 94089
•
Tel: (408) 222-8888
•
FAX: (408) 222-4895
•
www.supertex.com
SUPERTEX [ Supertex, Inc ]
