iru3055 International Rectifier Corp., iru3055 Datasheet - Page 5

• Manufacturer Part Number: iru3055
• Description: 5-bit Programmable 3-phase Synchronous Buck Controller Ic -
• Manufacturer: International Rectifier Corp.

PIN#
Rev. 1.4
08/13/02
15
16
17
28
18
19
20
21
31
22
30
32
23
27
34
24
26
35
25
36
29
33
PIN SYMBOL
OCGnd
PGood
PGnd3
PGnd2
PGnd1
OCSet
HDrv3
HDrv2
HDrv1
LDrv3
LDrv2
LDrv1
Fault
V
V
Gnd
V
V
SD
Ref
NC
CH12
CL23
CH3
CL1
Fault detector. When the output exceeds the OVP trip point, the fault pin switches to
2.8V and pulls down the soft-start.
This pin is connected to the drain of the synchronous MOSFET in channel 1 of the Core
supply and it provides the positive sensing for the internal current sensing circuitry. An
external resistor programs the over current threshold depending on the R
power MOSFET.
Analog ground for internal reference and control circuitry. Connect to PGnd with a short
trace.
Shut down pin. Pulling-up this pin disables the outputs.
Power good pin. This pin is a collector output that switches Low when the output of the
converter is not within 610%(typ) of the nominal output voltage.
2V reference output.
These pins power the high side MOSFET driver. A minmum 1mF ceramic cap must be
connected from these pins to ground to provide peak drive current capability.
Output drivers for the high side power MOSFET.
These pins serve as the ground pins and must be connected directly to the ground plane.
A high frequency capacitor (0.1 to 1mF) must be connected from pins V
V
Output driver for the synchronous power MOSFET.
These pins are connected to the 12V supply and serves as the power Vcc pin for the low
side output drivers. A high frequency capacitor (0.1 to 1mF) must be connected directly
from these pins to PGnd1, PGnd2 and PGnd3 pins in order to supply the peak current to
the power MOSFET during the transitions.
No connection.
This pin is connected from the source of the synchronous MOSFET in channal 1 of the
Core supply and it provides the reference point for the internal current sensing circuitry.
PIN DESCRIPTION
CH3
, V
CH12
to PGnd1, 2 and 3 for noise free operation.
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IRU3055
CL1
DS(ON)
, V
CL23
of the
and
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