iru3046 International Rectifier Corp., iru3046 Datasheet - Page 3

• Manufacturer Part Number: iru3046
• Description: Dual Synchronous Pwm Controller With Current Sharing Circuitry And Ldo 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. 1.9
09/27/02
5,6
21
16
1
2
3
4
7
8
9
Comp1, Comp2
PIN SYMBOL
VcH2
VcH1
Sync
V
Vp2
Vcc
Fb2
Fb1
Rt
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 2-channel mode it is connected to
V
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 2-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.
The switching frequency can be programmed between 200KHz and 400KHz by connect-
ing a resistor between Rt and Gnd. By floating the pin, the switching frequency will be
200KHz and by grounding the pin, the switching frequency will be 400KHz.
The internal oscillator may be synchronized to an external clock via this pin.
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 mini-
mum of 1mF, high frequency capacitor must be connected from these pins to PGnd to
provide peak drive current capability.
REF
PIN DESCRIPTION
pin when Fb2 is connected to the resistor divider to set the output voltage.
V
V
I
PG
PG
PG
PG
PG
PG
LDO(BIAS)
SYM
V
OS(ERR)2
Freq
FB
SS
T
V
g
g
T
T
I
I
I
RAMP
LDO
FB1
FB2
Tr
Tf
OFF
LDO
m1
m2
DB
ON
PG
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
Rt=Gnd
C
C
Fb=1V, Freq=200KHz
Fb=1.5V
L
L
=1500pF
=1500pF
www.irf.com
TEST CONDITION
P2
1.225
MIN
180
300
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
350
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
IRU3046
1.275
MAX
220
450
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