iru3039 International Rectifier Corp., iru3039 Datasheet - Page 4

• Manufacturer Part Number: iru3039
• Description: Ic Ctrlr Pwm Sync Switch 20-mlpq
• Manufacturer: International Rectifier Corp.

IRU3039(PbF)
PIN DESCRIPTIONS
PIN#
1 1,13,14
BLOCK DIAGRAM
4
2,3,5,
15
16
17
18
19
20
SS / SD
OCSet
Comp
V
POR
Vcc
REF
V
Fb
PIN SYMBOL
P
3V
16
17
20
19
18
4
1
SS / SD
OCSet
Comp
V
0.8V
NC
Fb
V
OUT2
22uA
P
25K
25K
3V
28uA
OC Comp
1.25V
Output of internal regulator. The output is protected for short circuit. A high frequency
capacitor is recommended to be connected from this pin to ground.
This pin is connected to the Drain of the lower MOSFET via an external resister and it
provides the positive sensing for the internal current sensing circuitry. The external resis-
tor programs the current limit threshold depending on the R
An external capacitor can be placed in parallel with the programming resistor to provide
high frequency noise filtering.
This pin provides soft-start for the switching regulator. An internal current source charges
an external capacitor that is connected from this pin to ground which ramps up the output
of the switching regulator, preventing it from overshooting as well as limiting the input
current. The converter can be shutdown by pulling this pin down below 0.4V.
Compensation pin of the error amplifier. An external resistor and capacitor network is
typically connected from this pin to ground to provide loop compensation.
This pin is connected directly to the output of the switching regulator via resistor divider to
provide feedback to the Error amplifier.
Non-inverting input of error amplifier.
No connection.
PIN DESCRIPTION
64uA Max
Figure 2 - Simplified block diagram of the IRU3039.
3.5V
Vc
4V
Error Amp
0.2V
0.2V
0.4V
Rt
Ct
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Generator
Oscillator
Regulator
Error Comp
Bias
FbLo Comp
6V
Enbl
3V
1.25V
POR
Reset Dom
S
R
POR
Q
DS(ON)
of the power MOSFET.
Vcc
15
12
10
6
7
9
8
V
Rt
Vc
HDrv
LDrv
PGnd
Gnd
OUT2