iru3055 International Rectifier Corp., iru3055 Datasheet - Page 4

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

IRU3055
PIN DESCRIPTIONS
PIN#
4
10
12
13
14
11
1
2
3
4
5
6
7
8
9
D4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
PIN SYMBOL
Comp
D3
CS1
CS2
CS3
V
Vcc
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
SS
D0
D1
D2
D3
D4
Fb
Rt
SET
D2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
This pin programs the oscillator frequency in the range of 50KHz to 500KHz with an
external resistor connected from this pin to the ground.
Compensation for error amplifier.
This pin is connected directly to the output of the Core supply to provide feedback to the
Error amplifier.
This pin provides the soft-start for the switching regulator. An internal current source
charges an external capacitor that is connected from this pin to the ground which ramps
up the outputs of the switching regulator, preventing the outputs from overshooting as
well as limiting the input current. The second function of the Soft-Start cap is to provide
long off time (HICCUP) for the synchronous MOSFET during current limiting.
Current sense feedback for channel 1, 2, 3.
5V supply voltage.
Output of the DAC.
LSB input to the DAC that programs the output voltage. This pin is internally connected
to 3.3V by a 16K resistor. This pin can be pulled up externally by a 10K resistor to 5V
supply. This pin programs the output voltage in 25mV steps based on the VID table.
Input to the DAC that programs the output voltage. This pin is internally connected to
3.3V by a 16K resistor. This pin can be pulled up externally by a 10K resistor to 5V
supply.
Input to the DAC that programs the output voltage. This pin is internally connected to
3.3V by a 16K resistor. This pin can be pulled up externally by a 10K resistor to 5V
supply.
Input to the DAC that programs the output voltage. This pin is internally connected to
3.3V by a 16K resistor. This pin can be pulled up externally by a 10K resistor to 5V
supply.
MSB input to the DAC that programs the output voltage. This pin is internally connected
to 3.3V by a 16K resistor. This pin can be pulled up externally by a 10K resistor to 5V
supply.
PIN DESCRIPTION
D1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
Table 1 - Set point voltage (Vs) vs. VID codes.
D0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1.075
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
1.325
1.350
1.375
1.400
1.425
1.450
Vs
www.irf.com
D4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
D3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
D2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
D1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
D0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1.475
1.500
1.525
1.550
1.575
1.600
1.625
1.650
1.675
1.700
1.725
1.750
1.475
1.800
1.825
1.850
Vs
08/13/02
Rev. 1.4