iru3047 International Rectifier Corp., iru3047 Datasheet - Page 3

• Manufacturer Part Number: iru3047
• Description: Dual Synchronous Controller With Current Sharing Circuitry Controller
• Manufacturer: International Rectifier Corp.

PARAMETER
Soft-Start Section
Charge Current
Power Good Section
Fb1 Lower Trip Point
Fb1 Upper Trip Point
Fb2 Lower Trip Point
Fb2 Upper Trip Point
Fb3 Lower Trip Point
Fb3 Upper Trip Point
Power Good Voltage OK
Error Amp Section
Fb Voltage Input Bias Current
Fb Voltage Input Bias Current
Transconductance 1
Transconductance 2
Input Offset Voltage for PWM2
Oscillator Section
Frequency
Ramp Amplitude
Output Drivers Section
Rise Time
Fall Time
Dead Band Time
Max Duty Cycle
Min Duty Cycle
LDO Controller Section
Drive Current
Fb Voltage
Input Bias Current
PIN DESCRIPTIONS
PIN#
Rev. 1.0
09/09/02
3,18
7,14
8,13
5,6
1
2
4
Comp1, Comp2
HDrv2, HDrv1
PIN SYMBOL
VcH2, VcH1
Fb2, Fb1
V
Vp2
Vcc
REF
Reference Voltage.
Non-inverting input to the second error amplifier, in the current sharing mode it is con-
nected to the programming resistor. In independent two channel mode it is connected to
the reference voltage (Pin1) when Fb2 is connected to the resistor divider to set the
output voltage.
Inverting inputs to the error amplifiers, in current sharing mode Fb1 is connected to a
resistor divider to set the output voltage and Fb2 is connected to programming resistor to
achieve current sharing. In independent two channel mode, these pins work as feedback
inputs for each channel.
Supply voltage for the internal blocks of the IC.
Compensation pins for the error amplifiers.
Supply voltage for the high side output drivers. These are connected to voltages that
must be at least 4V higher than their bus voltages (assuming 5V threshold MOSFET). A
minimum of 1mF high frequency capacitor must be connected from these pins to PGnd
pin to provide peak drive current capability.
Output driver for high side power MOSFET. Connect a diode, such as BAT54 or 1N4148,
from these pins to ground for the application when the inductor current goes negative
(Source/Sink), soft-start at no load and for fast load transient from full load to no load.
PIN DESCRIPTION
V
V
I
PG
PG
PG
PG
PG
PG
LDO(BIAS)
SYM
V
OS(ERR)2
Freq
FB
SS
T
V
T
T
I
I
I
g
g
RAMP
LDO
FB1
FB2
Tr
Tf
OFF
LDO
DB
ON
PG
m1
m2
FB1H
FB2H
FB3H
FB1L
FB2L
FB3L
IB
SS=0V
Fb1 Ramping Down
Fb1 Ramping Up
Fb2 Ramping Down
Fb2 Ramping Up
Fb3 Ramping Down
Fb3 Ramping Up
5K resistor pulled up to 5V
SS=3V
SS=0V
Fb2 to V
Rt=Open
C
C
Fb=1V, Freq=200KHz
Fb=1.5V
L
L
=1500pF
=1500pF
www.irf.com
TEST CONDITION
P2
1.225
MIN
180
4.5
15
50
85
30
-2
0
0.9
1.1
0.9
1.1
0.9
1.1
TYP
1.25
1.25
-0.1
400
600
200
150
4.8
-64
0.5
25
35
50
90
45
V
V
V
V
V
V
0
0
REF
REF
REF
REF
REF
REF
IRU3047
1.275
MAX
220
100
100
250
30
+2
5
2
UNITS
mmho
mmho
KHz
mV
mA
mA
mA
mA
mA
ns
ns
ns
%
%
V
V
V
V
V
V
V
V
V
3