TSOP32438SS1F Vishay, TSOP32438SS1F Datasheet - Page 2

• Manufacturer Part Number: TSOP32438SS1F
• Manufacturer: Vishay

Specifications of TSOP32438SS1F

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Si9122
Vishay Siliconix
TECHNICAL DESCRIPTION
Si9122 is a voltage mode controller for the half-bridge
topology. With 100 V depletion mode MOSFET capability,
the Si9122 is capable of powering directly from the high
voltage bus to V
or may be powered through an external regulator directly
through the V
peak efficiency throughout the entire line and load range. In
order to simplify the traditional secondary synchronous
rectification, Si9122 provides intelligent gate drive signals to
control the secondary MOSFETs. With independent gate
drive signals from the controller, transformer design is no
longer limited by the gate to a source rating of the MOSFETs.
Si9122 provides constant V
voltage to minimize the gate charge loss as well as
conduction loss. A break-before-make function is included to
DETAILED BLOCK DIAGRAM
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2
REG_COMP
V
CC
INDET
V
CS2
CS1
CC
REF
EP
SS
pin. With PWM control, Si9122 provides
through an external PNP pass transistor,
20 µA
Error Amplifier
GS
voltage, independent of line
60 kΩ
Pre-Regulator
I
SS
V
V
Over Current Protection
IN
REF
8 V
132 kΩ
+
-
V REF
-
+
GND
2
V
CC
9.1 V
Peak DET
8.8 V
+
-
+
-
+
-
550 mV
Comparator
+
-
V
V
V
UVLO
PWM
Figure 2.
UV
SD
Duty Cycle
C
Control
prevent shoot through current or transformer shorting.
Adjustable Break-Before-Make time is incorporated into the
IC and is programmable by an external resistor value.
Si9122 is packaged in TSSOP-20 and MLP65-20 packages.
Both TSSOP-20 and MLP65-20 packages are available in
lead (Pb)-free option. In order to satisfy the stringent ambient
temperature requirements, Si9122 is rated to handle the
industrial temperature range of - 40 °C to 85 °C. When a
situation arises which results in a rapid increase in primary
(or secondary current) such as output shorted or start-up
with a large output capacitor, control of the PWM generator
is handed over to the current loop. Monitoring of the load
current is by means of a sense resistor on the primary low-
side switch.
L_CONT
V
FF
Ramp
BBM
Control
Timing
Driver
R
OSC
and
OSC
OTP
High-Side
Primary
Driver
Si9122
Low-Side
Driver
Int
S-80038-Rev. J, 14-Jan-08
Document Number: 71815
SYNC
Driver High
SYNC
Driver Low
V
V
V
CC
CC
CC
BST
D
L
D
PGND
SR
SR
X
H
L
H
L