SI9119DB Vishay, SI9119DB Datasheet - Page 5

• Manufacturer Part Number: SI9119DB
• Description: Pulse Width Modulation (PWM) Controller IC
• Manufacturer: Vishay

Specifications of SI9119DB

• Silicon Manufacturer: Vishay
• Application Sub Type: Switch Mode
• Kit Application Type: Power Management
• Silicon Core Number: SI9119
• Kit Contents: Board
• Input Voltage Primary Min: 10V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

DETAILED DESCRIPTION
Pre-Regulator/Start-Up Section
Due to the low quiescent current requirement of the Si9120
control circuitry, bias power can be supplied from the
unregulated input power source, from an external regulated
low-voltage supply, or from an auxiliary “bootstrap” winding on
the output inductor or transformer.
When power is first applied during start-up, +V
draw a constant current. The magnitude of this current is
determined by a high-voltage depletion MOSFET which is
connected between +V
circuitry provides initial power to the IC by charging an external
bypass capacitance connected to the V
current is disabled when V
forced to exceed the 8.6-V threshold, then V
regulated to a nominal value of 8.6 V by the pre-regulator
circuit.
As the supply voltage rises toward the normal operating
conditions, an internal undervoltage (UV) lockout circuit keeps
the output driver disabled until V
lockout threshold (typically 8.1 V). This guarantees that the
Document Number: 70006
S-42042—Rev. H, 15-Nov-04
PIN CONFIGURATIONS AND ORDERING INFORMATION
OSC OUT
OUTPUT
SENSE
+V
−V
NC*
NC*
V
CC
IN
IN
1
2
3
4
5
6
7
8
IN
Dual-In-Line
Top View
and V
CC
exceeds 8.6 V. If V
CC
Si9120DY
Si9120DY-T1
Si9120DY-T1—E3
Si9120DJ
Si9120DJ—E3
CC
Part Number
exceeds the undervoltage
16
15
14
13
12
10
11
9
(pin 7). This start-up
CC
BIAS
FB
COMP
RESET
SHUTDOWN
V
DISCHARGE
OSC IN
pin. The constant
REF
ORDERING INFORMATION
IN
CC
(pin 1) will
CC
Temperature Range
will be
is not
−40 to 85_C
control logic will be functioning properly and that sufficient gate
drive voltage is available before the MOSFET turns on. The
design of the IC is such that the undervoltage lockout threshold
will be at least 300 mV less than the pre-regulator turn-off
voltage. Power dissipation can be minimized by providing an
external power source to V
source is always disabled.
Note: When driving large MOSFETs at high frequency without
a bootstrap V
may exceed the power rating of the IC package. For operation
of +V
series with +V
resistor is recommended.
BIAS
To properly set the bias for the Si9120, a 390-kW resistor
should be tied from BIAS (pin 16) to −V
determines the magnitude of bias current in all of the analog
sections and the pull-up current for the SHUTDOWN and
RESET pins. The current flowing in the bias resistor is
nominally 15 mA.
OSC OUT
OUTPUT
SENSE
IN
+V
−V
> 250 V, a 10-kW,
V
CC
IN
IN
Note: Pins 2 and 3 are removed
CC
1
4
5
6
7
8
Package
IN
SOIC-16
PDIP 16
PDIP-16
supply, power dissipation in the pre-regulator
(Pin 1). For +V
Top View
SOIC
1
CC
/
4
-W resistor should be placed in
16
15
14
13
12
11
10
9
such that the constant current
IN
Vishay Siliconix
BIAS
FB
COMP
RESET
SHUTDOWN
V
DISCHARGE
OSC IN
REF
> 380 V, a 15-kW,
IN
(pin 6). This
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Si9120
1
/
4
-W
5