INTERSIL HIP6021EVAL1

HIP6021
Data Sheet
February 1999
Advanced PWM and Triple Linear Power
Controller
The HIP6021 provides the power control and protection for
four output voltages in high-performance, graphics intensive
microprocessor and computer applications. The IC
integrates a voltage-mode PWM controller and three linear
controllers, as well as the monitoring and protection
functions into a 28-pin SOIC package. The PWM controller
regulates the microprocessor core voltage with a
synchronous-rectified buck converter. The linear controllers
regulate the computer system’s AGP 1.5V or 3.3V bus
power, the 1.5V GTL bus power, and the 1.8V power for the
North/South Bridge core voltage and/or cache memory
circuits. The HIP6021 includes an Intel-compatible, TTL
5-input digital-to-analog converter (DAC) that adjusts the
core PWM output voltage from 1.3VDC to 2.05VDC in 0.05V
steps and from 2.1VDC to 3.5VDC in 0.1V increments. The
precision reference and voltage-mode control provide ±1%
static regulation. The AGP bus power linear controller’s
output (VOUT2) is user-selectable, through a TTL-compatible
signal applied at the SELECT pin, for levels of 1.5V or 3.3V
with ±3% accuracy. Based on the status of the FIX pin, the
other two linear regulators provide either fixed output
voltages of 1.5V±3% (VOUT3) and 1.8V±3% (VOUT4), or
user-adjustable by means of an external resistor divider. All
linear controllers can employ either N-channel MOSFETs or
bipolar NPNs for the pass transistor.
The HIP6021 monitors all the output voltages. A single
Power Good signal is issued when the core is within ±10% of
the DAC setting and all other outputs are above their undervoltage levels. Additional built-in over-voltage protection for
the core output uses the lower MOSFET to prevent output
voltages above 115% of the DAC setting. The PWM
controller’s over-current function monitors the output current
by using the voltage drop across the upper MOSFET’s
rDS(ON).
PART NUMBER
HIP6021CB
HIP6021EVAL1
TEMP.
RANGE (oC)
0 to 70
PACKAGE
28 Ld SOIC
Evaluation Board
PKG.
NO.
M28.3
• Provides 4 Regulated Voltages
- Microprocessor Core, AGP Bus, Memory, and GTL Bus
Power
• Drives N-Channel MOSFETs
• Linear Regulator Drives Compatible with both MOSFET
and Bipolar Series Pass Transistors
• Fixed or Externally Resistor-Adjustable Linear Outputs
(FIX Pin)
• Simple Single-Loop Control Design
- Voltage-Mode PWM Control
• Fast PWM Converter Transient Response
- High-Bandwidth Error Amplifier
- Full 0% to 100% Duty Ratio
• Excellent Output Voltage Regulation
- Core PWM Output: ±1% Over Temperature
- Other Outputs: ±3% Over Temperature
• TTL-Compatible 5-Bit DAC Microprocessor Core Output
Voltage Selection
- Wide Range . . . . . . . . . . . . . . . . . . . 1.3VDC to 3.5VDC
• Power-Good Output Voltage Monitor
• Over-Voltage and Over-Current Fault Monitors
- Switching Regulator Does Not Require Extra Current
Sensing Element, Uses MOSFET’s rDS(ON)
• Small Converter Size
- Constant Frequency Operation
- 200kHz Free-Running Oscillator; Programmable From
50kHz to Over 1MHz
- Small External Component Count
Pinout
HIP6021 (SOIC)
TOP VIEW
• Motherboard Power Regulation for Computers
27 UGATE
VID4 3
26 PHASE
VID3 4
25 LGATE
VID2 5
24 PGND
VID1 6
23 OCSET
VID0 7
22 VSEN1
21 FB
SD 9
20 COMP
VSEN2 10
19 VSEN3
SELECT 11
SS 12
FAULT/RT 13
VSEN4 14
2-296
28 VCC
FIX 2
PGOOD 8
Applications
4684
Features
DRIVE2 1
Ordering Information
File Number
18 DRIVE3
17 GND
16 VAUX
15 DRIVE4
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
http://www.intersil.com or 407-727-9207 | Copyright © Intersil Corporation 1999
SELECT
VSEN2
DRIVE2
VSEN4
DRIVE4
DRIVE3
-
+
-
+
+
-
1.5V
or
3.3V
x 0.75
-
+
-
+
VAUX
-
+
1.26V
x 0.75
-
2-297
LUV
FIX
SD
FAULT / RT
SS
OV
28µA
VCC
SOFTINHIBIT
START
AND FAULT
FAULT
LOGIC
LINEAR
UNDERVOLTAGE
OSCILLATOR
-
+
+
VSEN3
4.5V
DACOUT
FB
ERROR
AMP1
x 1.15
x 0.90
x 1.10
-
+
-
+
-
+
+
-
VSEN1
COMP
OC1
PWM1
VID1
POWER-ON
VCC
SYNCH
DRIVE
GATE
CONTROL
DRIVE1
RESET (POR)
VID4
VID3
VID2
TTL D/A
CONVERTER
(DAC)
PWM
COMP1
VID0
-
+
-
+
200µA
OCSET
VCC
VCC
GND
PGND
LGATE
PHASE
UGATE
PGOOD
VAUX
HIP6021
Block Diagram
HIP6021
Simplified Power System Diagram
+5VIN
+3.3VIN
Q1
LINEAR
CONTROLLER
Q3
VOUT1
PWM
CONTROLLER
Q2
VOUT2
HIP6021
Q4
VOUT3
LINEAR
CONTROLLER
LINEAR
CONTROLLER
Q5
VOUT4
Typical Application
+12VIN
+5VIN
LIN
CIN
VCC
OCSET
+3.3VIN
POWERGOOD
PGOOD
Q3
VOUT2
DRIVE2
UGATE
1.5V OR 3.3V
VSEN2
Q1
LOUT1
PHASE
COUT2
LGATE
PGND
SELECT
TYPEDET
VSEN1
VAUX
HIP6021
Q4
DRIVE3
VOUT3
1.5V
FB
COMP
VSEN3
COUT3
FIX
FAULT / RT
VID0
DRIVE4
Q5
VOUT4
1.8V
VID1
VID2
VSEN4
VID3
SS
COUT4
VID4
CSS
GND
2-298
Q2
COUT1
VOUT1
1.3V TO 3.5V
HIP6021
Absolute Maximum Ratings
Thermal Information
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +15V
PGOOD, RT/FAULT, DRIVE, PHASE,
and GATE Voltage . . . . . . . . . . . . . . . GND - 0.3V to VCC + 0.3V
Input, Output or I/O Voltage . . . . . . . . . . . . . . . . . . GND -0.3V to 7V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 1
Thermal Resistance (Typical, Note 1)
θJA (oC/W)
SOIC Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
70
Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC
(SOIC - Lead Tips Only)
Operating Conditions
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . +12V ±10%
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . 0oC to 70oC
Junction Temperature Range . . . . . . . . . . . . . . . . . . . 0oC to 125oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
Recommended Operating Conditions, Unless Otherwise Noted. Refer to Block and Simplified Power System
Diagrams, and Typical Application Schematic
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
UGATE, LGATE, DRIVE2, DRIVE3, and
DRIVE4 Open
-
9
-
mA
Rising VCC Threshold
VOCSET = 4.5V
-
-
10.4
V
Falling VCC Threshold
VOCSET = 4.5V
8.2
-
-
V
Rising VAUX Threshold
VOCSET = 4.5V
-
2.5
-
V
VAUX Threshold Hysteresis
VOCSET = 4.5V
-
0.5
-
V
-
1.26
-
V
RT = OPEN
185
200
215
kHz
6kΩ < RT to GND < 200kΩ
-15
-
+15
%
-
1.9
-
VP-P
DAC(VID0-VID4) Input Low Voltage
-
-
0.8
V
DAC(VID0-VID4) Input High Voltage
2.0
-
-
V
DACOUT Voltage Accuracy
-1.0
-
+1.0
%
-
1.265
-
V
-2.5
-
+2.5
%
-
3
-
%
VCC SUPPLY CURRENT
Nominal Supply Current
ICC
POWER-ON RESET
Rising VOCSET Threshold
OSCILLATOR
Free Running Frequency
FOSC
Total Variation
∆VOSC
Ramp Amplitude
RT = Open
DAC AND BANDGAP REFERENCE
Bandgap Reference Voltage
VBG
Bandgap Reference Tolerance
LINEAR REGULATORS (OUT2, OUT3, AND OUT4)
Regulation (All Linears)
VSEN2 Regulation Voltage
VREG2
SELECT < 0.8V
-
1.5
-
V
VSEN2 Regulation Voltage
VREG2
SELECT > 2.0V
-
3.3
-
V
VSEN3 Regulation Voltage
VREG3
-
1.5
-
V
VSEN4 Regulation Voltage
VREG4
-
1.8
-
V
VSEN Rising
-
75
-
%
Under-Voltage Hysteresis (VSEN/VREG)
VSEN Falling
-
7
-
%
Output Drive Current (All Linears)
VAUX-VDRIVE > 0.6V
20
40
-
mA
Under-Voltage Level (VSEN/VREG)
2-299
VSENUV
HIP6021
Electrical Specifications
Recommended Operating Conditions, Unless Otherwise Noted. Refer to Block and Simplified Power System
Diagrams, and Typical Application Schematic (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
-
88
-
dB
-
15
-
MHz
COMP = 10pF
-
6
-
V/µs
SYNCHRONOUS PWM CONTROLLER ERROR AMPLIFIER
DC Gain
Gain-Bandwidth Product
GBWP
Slew Rate
SR
PWM CONTROLLER GATE DRIVER
UGATE Source
IUGATE
VCC = 12V, VUGATE = 6V
-
1
-
A
UGATE Sink
RUGATE
VGATE-PHASE = 1V
-
1.7
3.5
Ω
LGATE Source
ILGATE
VCC = 12V, VLGATE = 1V
-
1
-
A
LGATE Sink
RLGATE
VLGATE = 1V
-
1.4
3.0
Ω
VSEN1 Rising
-
115
120
%
PROTECTION
VSEN1 Over-Voltage (VSEN1/DACOUT)
FAULT Sourcing Current
IOVP
VFAULT/RT = 2.0V
-
8.5
-
mA
OCSET1 Current Source
IOCSET
VOCSET = 4.5VDC
170
200
230
µA
-
28
-
µA
Soft-Start Current
ISS
POWER GOOD
VSEN1 Upper Threshold
(VSEN1/DACOUT)
VSEN1 Rising
108
-
110
%
VSEN1 Under-Voltage
(VSEN1/DACOUT)
VSEN1 Rising
92
-
94
%
VSEN1 Hysteresis (VSEN1/DACOUT)
Upper/Lower Threshold
-
2
-
%
IPGOOD = -4mA
-
-
0.8
V
PGOOD Voltage Low
VPGOOD
Typical Performance Curves
100
CUGATE1 = CUGATE2 = CLGATE1 = C
C = 4800pF
VIN = 5V
80
VCC = 12V
RT PULLUP
TO +12V
ICC (mA)
RESISTANCE (kΩ)
1000
100
60
C = 3600pF
40
C = 1500pF
10
RT PULLDOWN TO VSS
10
100
SWITCHING FREQUENCY (kHz)
FIGURE 1. RT RESISTANCE vs FREQUENCY
2-300
20
C = 660pF
1000
0
100
200
300
400
500
600
700
800
SWITCHING FREQUENCY (kHz)
900
FIGURE 2. BIAS SUPPLY CURRENT vs FREQUENCY
1000
HIP6021
Functional Pin Descriptions
VCC (Pin 28)
Provide a 12V bias supply for the IC to this pin. This pin also
provides the gate bias charge for all the MOSFETs
controlled by the IC. The voltage at this pin is monitored for
Power-On Reset (POR) purposes.
GND (Pin 17)
Signal ground for the IC. All voltage levels are measured with
respect to this pin.
PGND (Pin 24)
This is the power ground connection. Tie the synchronous
PWM converter’s lower MOSFET source to this pin.
VAUX (Pin 16)
This pin provides boost current for the linear regulators’
output drives in the event bipolar NPN transistors (instead
of N-channel MOSFETs) are employed as pass elements.
The voltage at this pin is monitored for power-on reset
(POR) purposes.
SS (Pin 12)
Connect a capacitor from this pin to ground. This capacitor,
along with an internal 28µA current source, sets the
soft-start interval of the converter.
FAULT / RT (Pin 13)
This pin provides oscillator switching frequency adjustment.
By placing a resistor (RT) from this pin to GND, the nominal
200kHz switching frequency is increased according to the
following equation:
6
5 × 10
Fs ≈ 200KHz + --------------------R T ( kΩ )
(RT to GND)
Conversely, connecting a resistor from this pin to VCC
reduces the switching frequency according to the following
equation:
7
4 × 10
Fs ≈ 200KHz – --------------------R T ( kΩ )
(RT to 12V)
Nominally, the voltage at this pin is 1.26V. In the event of an
over-voltage or over-current condition, this pin is internally
pulled to VCC.
PGOOD (Pin 8)
PGOOD is an open collector output used to indicate the
status of the output voltages. This pin is pulled low when the
synchronous regulator output is not within ±10% of the
DACOUT reference voltage or when any of the other outputs
are below their under-voltage thresholds.
the soft-start capacitor, disabling all the outputs. Dedicated
internal circuitry insures the core output voltage does not go
negative during this process. When re-enabled, the IC
undergoes a new soft-start cycle. Left open, this pin is pulled
low by an internal pull-down resistor, enabling operation.
FIX (Pin 2)
Grounding this pin bypasses the internal resistor dividers
that set the output voltage of the 1.5V and 1.8V linear
regulators. This way, the output voltage of the two regulators
can be adjusted from 1.26V up to the input voltage (+3.3V or
+5V) by way of an external resistor divider connected at the
corresponding VSEN pin. The new output voltage set by the
external resistor divider can be determined using the
following formula:
R OUT 

V OUT = 1.265V ×  1 + -----------------
R

GND
where ROUT is the resistor connected from VSEN to the
output of the regulator, and RGND is the resistor connected
from VSEN to ground. Left open, the FIX pin is pulled high,
enabling fixed output voltage operation.
VID0, VID1, VID2, VID3, VID4 (Pins 7, 6, 5, 4 and 3)
VID0-4 are the TTL-compatible input pins to the 5-bit DAC.
The logic states of these five pins program the internal
voltage reference (DACOUT). The level of DACOUT sets the
microprocessor core converter output voltage, as well as the
coresponding PGOOD and OVP thresholds.
OCSET (Pin 23)
Connect a resistor from this pin to the drain of the respective
upper MOSFET. This resistor, an internal 200µA current
source, and the upper MOSFET’s on-resistance set the
converter over-current trip point. An over-current trip cycles
the soft-start function.
The voltage at this pin is monitored for power-on reset (POR)
purposes and pulling this pin low with an open drain device
will shutdown the IC.
PHASE (Pin 26)
Connect the PHASE pin to the PWM converter’s upper
MOSFET source. This pin represents the gate drive return
current path and is used to monitor the voltage drop across
the upper MOSFET for over-current protection.
UGATE (Pin 27)
Connect UGATE pin to the PWM converter’s upper MOSFET
gate. This pin provides the gate drive for the upper MOSFET.
LGATE (Pin 25)
The PGOOD output is open for ‘11111’ VID code.
Connect LGATE to the PWM converter’s lower MOSFET
gate. This pin provides the gate drive for the lower MOSFET.
SD (Pin 9)
COMP and FB (Pin 20, and 21)
This pin shuts down all the outputs. A TTL-compatible, logic
level high signal applied at this pin immediately discharges
COMP and FB are the available external pins of the PWM
converter error amplifier. The FB pin is the inverting input of the
2-301
HIP6021
error amplifier. Similarly, the COMP pin is the error amplifier
output. These pins are used to compensate the voltage-mode
control feedback loop of the synchronous PWM converter.
VSEN1 (Pin 22)
This pin is connected to the PWM converter’s output voltage.
The PGOOD and OVP comparator circuits use this signal to
report output voltage status and for over- voltage protection.
DRIVE2 (Pin 1)
Connect this pin to the gate of an external MOSFET. This pin
provides the drive for the AGP regulator’s pass transistor.
VSEN2 (Pin 10)
Connect this pin to the output of the AGP linear regulator.
The voltage at this pin is regulated to the level
predetermined by the logic-level status of the SELECT pin.
This pin is also monitored for under-voltage events.
either output voltage is achieved by applying the proper
logic level at the SELECT pin. The remaining two linear
controllers supply the 1.5V GTL bus power (VOUT3) and
the 1.8V memory power (VOUT4). All linear controllers are
designed to employ an external pass transistor.
Initialization
The HIP6021 automatically initializes upon receipt of input
power. Special sequencing of the input supplies is not
necessary. The Power-On Reset (POR) function continually
monitors the input supply voltages. The POR monitors the
bias voltage (+12VIN) at the VCC pin, the 5V input voltage
(+5VIN) on the OCSET pin, and the 3.3V input voltage
(+3.3VIN) at the VAUX pin. The normal level on OCSET is
equal to +5VIN less a fixed voltage drop (see over-current
protection). The POR function initiates soft-start operation
after all supply voltages exceed their POR thresholds.
Soft-Start
SELECT (Pin 11)
This pin determines the output voltage of the AGP bus linear
regulator. A low TTL input sets the output voltage to 1.5V,
while a high input sets the output voltage to 3.3V.
DRIVE3 (Pin 18)
Connect this pin to the gate of an external MOSFET. This pin
provides the drive for the 1.5V regulator’s pass transistor.
VSEN3 (Pin 19)
Connect this pin to the output of the 1.5V linear regulator.
This pin is monitored for under-voltage events.
DRIVE4 (Pin 15)
Connect this pin to the gate of an external MOSFET. This pin
provides the drive for the 1.8V regulator’s pass transistor.
VSEN4 (Pin 14)
Connect this pin to the output of the linear 1.8V regulator.
This pin is monitored for undervoltage events.
Description
Operation
The HIP6021 monitors and precisely controls 4 output
voltage levels (Refer to Block and Simplified Power System
Diagrams, and Typical Application Schematic). It is
designed for microprocessor computer applications with
3.3V, 5V, and 12V bias input from an ATX power supply.
The IC has a synchronous PWM controller and three linear
controllers. The PWM controller (PWM) is designed to
regulate the microprocessor core voltage (VOUT1). PWM
controller drives 2 MOSFETs (Q1 and Q2) in a
synchronous-rectified buck converter configuration and
regulates the microprocessor core voltage to a level
programmed by the 5-bit digital-to-analog converter (DAC).
One of the linear controllers is designed to regulate the
advanced graphics port (AGP) bus voltage (VOUT2) to a
digitally-programmable level of 1.5V or 3.3V. Selection of
2-302
The POR function initiates the soft-start sequence. Initially,
the voltage on the SS pin rapidly increases to approximately
1V (this minimizes the soft-start interval). Then an internal
28µA current source charges an external capacitor (CSS) on
the SS pin to 4.5V. The PWM error amplifier reference input
(+ terminal) and output (COMP pin) are clamped to a level
proportional to the SS pin voltage. As the SS pin voltage
slews from 1V to 4V, the output clamp allows generation of
PHASE pulses of increasing width that charge the output
capacitor(s). After the output voltage increases to
approximately 70% of the set value, the reference input
clamp slows the output voltage rate-of-rise and provides a
smooth transition to the final set voltage. Additionally, all
linear regulators’ reference inputs are clamped to a voltage
proportional to the SS pin voltage. This method provides a
rapid and controlled output voltage rise.
Figure 3 shows the soft-start sequence for the typical
application. At T0 the SS voltage rapidly increases to
approximately 1V. At T1, the SS pin and error amplifier
output voltage reach the valley of the oscillator’s triangle
wave. The oscillator’s triangular wave form is compared to
the clamped error amplifier output voltage. As the SS pin
voltage increases, the pulse-width on the PHASE pin
increases. The interval of increasing pulse-width continues
until each output reaches sufficient voltage to transfer
control to the input reference clamp. If we consider the 2.5V
core output (VOUT1) in Figure 3, this time occurs at T2.
During the interval between T2 and T3, the error amplifier
reference ramps to the final value and the converter
regulates the output a voltage proportional to the SS pin
voltage. At T3 the input clamp voltage exceeds the
reference voltage and the output voltage is in regulation.
The remaining outputs are also programmed to follow the
SS pin voltage. The PGOOD signal toggles ‘high’ when all
output voltage levels have exceeded their under-voltage
levels. See the Soft-Start Interval section under
HIP6021
fully charged to 4V (UP signal). An under-voltage on either
linear output (VSEN2, VSEN3, or VSEN4) is ignored until
after the soft-start interval (T4 in Figure 3). This allows
VOUT2 , VOUT3 , and VOUT4 to increase without fault at startup. Cycling the bias input voltage (+12VIN on the VCC pin off
then on) resets the counter and the fault latch.
PGOOD
0V
SOFT-START
(1V/DIV)
Over-Voltage Protection
0V
VOUT2 ( = 3.3V)
VOUT1 (DAC = 2.5V)
During operation, a short on the upper MOSFET of the PWM
regulator (Q1) causes VOUT1 to increase. When the output
exceeds the over-voltage threshold of 115% of DACOUT, the
over-voltage comparator trips to set the fault latch and turns
Q2 on. This blows the input fuse and reduces VOUT1. The
fault latch raises the FAULT/RT pin to VCC.
VOUT4 ( = 1.8V)
OUTPUT
VOLTAGES
(0.5V/DIV)
VOUT3 ( = 1.5V)
0V
A separate over-voltage circuit provides protection during
the initial application of power. For voltages on the VCC pin
below the power-on reset (and above ~4V), the output level
is monitored for voltages above 1.3V. Should VSEN1 exceed
this level, the lower MOSFET, Q2 is driven on.
Over-Current Protection
T0 T1
T2
TIME
T3
T4
FIGURE 3. SOFT-START INTERVAL
Applications Guidelines for a procedure to determine the
soft-start interval.
Fault Protection
All four outputs are monitored and protected against extreme
overload. A sustained overload on any output or an overvoltage on VOUT1 output (VSEN1) disables all outputs and
drives the FAULT/RT pin to VCC.
LUV
OVERCURRENT
LATCH
INHIBIT
S Q
OC1
R
0.15V
+
COUNTER
-
R
SS
+
4V
FAULT
LATCH
VCC
S Q
UP
-
POR
R
FAULT
OV
FIGURE 4. FAULT LOGIC - SIMPLIFIED SCHEMATIC
Figure 4 shows a simplified schematic of the fault logic. An
over-voltage detected on VSEN1 immediately sets the fault
latch. A sequence of three over-current fault signals also
sets the fault latch. The over-current latch is set dependent
upon the states of the over-current (OC), linear undervoltage (LUV) and the soft-start signals. A window
comparator monitors the SS pin and indicates when CSS is
2-303
All outputs are protected against excessive over-currents.
The PWM controller uses the upper MOSFET’s
on-resistance, rDS(ON) to monitor the current for protection
against shorted output. All linear controllers monitor their
respective VSEN pins for under-voltage events to protect
against excessive currents.
Figure 5 illustrates the over-current protection with an
overload on OUT1. The overload is applied at T0 and the
current increases through the inductor (LOUT1). At time T1,
the OVER-CURRENT comparator trips when the voltage
across Q1 (iD • rDS(ON)) exceeds the level programmed by
ROCSET. This inhibits all outputs, discharges the soft-start
capacitor (CSS) with a 10mA current sink, and increments
the counter. CSS recharges at T2 and initiates a soft-start
cycle with the error amplifiers clamped by soft-start. With
OUT1 still overloaded, the inductor current increases to trip
the over-current comparator. Again, this inhibits all outputs,
but the soft-start voltage continues increasing to 4V before
discharging. The counter increments to 2. The soft-start
cycle repeats at T3 and trips the over-current comparator.
The SS pin voltage increases to 4V at T4 and the counter
increments to 3. This sets the fault latch to disable the
converter. The fault is reported on the FAULT/RT pin.
The linear controllers operate in the same way as the PWM
in response to over-current faults. The differentiating factor
for the linear controllers is that they monitor the VSEN pins
for under-voltage events. Should excessive currents cause
the voltage at the VSEN pins to fall below the linear undervoltage threshold, the LUV signal sets the over-current
latch if CSS is fully charged. Blanking the LUV signal during
the CSS charge interval allows the linear outputs to build
above the under-voltage threshold during normal operation.
Cycling the bias input power off then on resets the counter
and the fault latch.
FAULT/RT
HIP6021
10V
0V
SOFT-START
COUNT
=1
INDUCTOR CURRENT
The OC trip point varies with MOSFET’s rDS(ON)
temperature variations. To avoid over-current tripping in the
normal operating load range, determine the ROCSET
resistor from the equation above with:
FAULT
REPORTED
COUNT
=2
COUNT
=3
1. The maximum rDS(ON) at the highest junction temperature.
4V
2. The minimum IOCSET from the specification table.
2V
3. Determine IPEAK for IPEAK > IOUT(MAX) + (∆I)/2, where
∆I is the output inductor ripple current.
For an equation for the ripple current see the section under
component guidelines titled ‘Output Inductor Selection’.
0V
OVERLOAD
APPLIED
OUT1 Voltage Program
0A
T0 T1
T2
T3
T4
TIME
FIGURE 5. OVER-CURRENT OPERATION
A resistor (ROCSET) programs the over-current trip level for
the PWM converter. As shown in Figure 6, the internal
200µA current sink, IOCSET develops a voltage across
ROCSET (VSET) that is referenced to VIN . The DRIVE
signal enables the over-current comparator (OVERCURRENT). When the voltage across the upper MOSFET
(VDS) exceeds VSET, the over-current comparator trips to
set the over-current latch. Both VSET and VDS are
referenced to VIN and a small capacitor across ROCSET
helps VOCSET track the variations of VIN due to MOSFET
switching. The over-current function will trip at a peak
inductor current (IPEAK) determined by:
I OCSET × R OCSET
I PEAK = ---------------------------------------------------r DS ( ON )
OVER-CURRENT TRIP:
V DS > V SET
VIN = +5V
i D × r DS ( ON ) > I OCSET × R OCSET
ROCSET
OCSET
IOCSET
200µA
OVERCURRENT
OC
iD
VCC
DRIVE
+
UGATE
+
VDS
PHASE
-
PWM
VSET +
V PHASE = V IN – V DS
V OCSET = V IN – V SET
GATE
CONTROL
FIGURE 6. OVER-CURRENT DETECTION
2-304
The output voltage of the PWM converter is programmed to
discrete levels between 1.3VDC and 3.5VDC . This output
(OUT1) is designed to supply the core voltage of Intel’s
advanced microprocessors. The voltage identification (VID)
pins program an internal voltage reference (DACOUT) with a
TTL-compatible 5-bit digital-to-analog converter. The level of
DACOUT also sets the PGOOD and OVP thresholds. Table
1 specifies the DACOUT voltage for the different
combinations of connections on the VID pins. The VID pins
can be left open for a logic 1 input, because they are
internally pulled up to an internal voltage of about 5V by a
10µA current source. Changing the VID inputs during
operation is not recommended and could toggle the PGOOD
signal and exercise the over-voltage protection. ‘11111’ VID
pin combination disables the IC and opens the PGOOD pin.
TABLE 1. OUT1 VOLTAGE PROGRAM
PIN NAME
VID4
VID3
VID2
VID1
VID0
NOMINAL
DACOUT
VOLTAGE
0
1
1
1
1
1.30
0
1
1
1
0
1.35
0
1
1
0
1
1.40
0
1
1
0
0
1.45
0
1
0
1
1
1.50
0
1
0
1
0
1.55
0
1
0
0
1
1.60
0
1
0
0
0
1.65
0
0
1
1
1
1.70
0
0
1
1
0
1.75
0
0
1
0
1
1.80
0
0
1
0
0
1.85
0
0
0
1
1
1.90
0
0
0
1
0
1.95
0
0
0
0
1
2.00
0
0
0
0
0
2.05
1
1
1
1
1
0
HIP6021
TABLE 1. OUT1 VOLTAGE PROGRAM (Continued)
PIN NAME
VID4
VID3
VID2
VID1
VID0
NOMINAL
DACOUT
VOLTAGE
1
1
1
1
0
2.1
1
1
1
0
1
2.2
1
1
1
0
0
2.3
1
1
0
1
1
2.4
1
1
0
1
0
2.5
1
1
0
0
1
2.6
1
1
0
0
0
2.7
VAUX
+3.3VIN
Q4
DRIVE3
VOUT3
VSEN3
RS3
RP3
COUT3
DRIVE4
Q5
1
0
1
1
1
2.8
1
0
1
1
0
2.9
1
0
1
0
1
3.0
1
0
1
0
0
3.1
1
0
0
1
1
3.2
1
0
0
1
0
3.3
1
0
0
0
1
3.4
1
0
0
0
0
3.5
NOTE: 0 = connected to GND, 1 = open or connected to 5V through
pull-up resistors
OUT2 Voltage Selection
The AGP regulator output voltage is internally set to one of
two discrete levels, based on the status of the SELECT pin.
SELECT pin is internally pulled ‘high’, such that left open,
the AGP output voltage is by default set to 3.3V. The other
discrete setting available is 1.5V, which can be obtained by
grounding the SELECT pin using a jumper or another
suitable method capable of sinking a few tens of
microamperes. The status of the SELECT pin cannot be
changed during operation of the IC without immediately
causing a fault condition.
OUT3 and OUT4 Voltage Adjustability
The GTL bus voltage (1.5V, OUT3) and the chip set and/or
cache memory voltage (1.8V, OUT4) are internally set for
simple, low-cost implementation in typical Intel motherboard
architectures. However, if different voltage settings are
desired for these two outputs, the FIX pin provides the
necessary adaptability. Left open (NC), this pin sets the fixed
output voltages described above. Grounding this pin allows
both output voltages to be set by means of external resistor
dividers as shown in Figure 7.
HIP6021
VOUT4
VSEN4
RS4
COUT4
RP4
FIX
R S

V OUT = V BG ×  1 + --------
R P

FIGURE 7. ADJUSTING THE OUTPUT VOLTAGE OF
OUTPUTS 3 AND 4
Application Guidelines
Soft-Start Interval
Initially, the soft-start function clamps the error amplifier’s
output of the PWM converter. This generates PHASE pulses
of increasing width that charge the output capacitor(s). After
the output voltage increases to approximately 70% of the set
value, the reference input of the error amplifier is clamped to
a voltage proportional to the SS pin voltage. The resulting
output voltages start-up as shown in Figure 3.
The soft-start function controls the output voltage rate of rise
to limit the current surge at start-up. The soft-start interval and
the surge current are programmed by the soft-start capacitor,
CSS. Programming a faster soft-start interval increases the
peak surge current. The peak surge current occurs during the
initial output voltage rise to 70% of the set value.
Shutdown
The HIP6021 features a dedicated shutdown pin (SD). A
TTL-compatible, logic high signal applied to this pin shuts
down (disables) all four outputs and discharges the soft-start
capacitor. Following a shutdown, a logic low signal
re-enables the outputs through initiation of a new soft-start
cycle. Left open this pin will asses a logic low state, due to its
internal pull-down resistor, thus enabling normal operation of
all outputs.
The PWM output does not switch until the soft-start voltage
(VSS) exceeds the oscillator’s valley voltage. The references
on each linear’s error amplifier are clamped to the soft-start
voltage. Holding the SS pin low (with an open drain or
collector signal) turns off all four regulators.
The ‘11111’ VID code also shuts down the IC.
2-305
HIP6021
Layout Considerations
MOSFETs switch very fast and efficiently. The speed with
which the current transitions from one device to another
causes voltage spikes across the interconnecting
impedances and parasitic circuit elements. The voltage
spikes can degrade efficiency, radiate noise into the circuit,
and lead to device over-voltage stress. Careful component
layout and printed circuit design minimizes the voltage
spikes in the converter. Consider, as an example, the turnoff transition of the upper PWM MOSFET. Prior to turn-off,
the upper MOSFET was carrying the full load current.
During the turn-off, current stops flowing in the upper
MOSFET and is picked up by the lower MOSFET or
Schottky diode. Any inductance in the switched current
path generates a large voltage spike during the switching
interval. Careful component selection, tight layout of the
critical components, and short, wide circuit traces minimize
the magnitude of voltage spikes. See the Application Note
ANTBD for evaluation board drawings of the component
placement and printed circuit board.
There are two sets of critical components in a DC-DC
converter using a HIP6020 controller. The switching power
components are the most critical because they switch large
amounts of energy, and as such, they tend to generate
equally large amounts of noise. The critical small signal
components are those connected to sensitive nodes or
those supplying critical bypass current.
The power components and the controller IC should be
placed first. Locate the input capacitors, especially the highfrequency ceramic decoupling capacitors, close to the power
switches. Locate the output inductor and output capacitors
between the MOSFETs and the load. Locate the PWM
controller close to the MOSFETs.
The critical small signal components include the bypass
capacitor for VCC and the soft-start capacitor, CSS . Locate
these components close to their connecting pins on the
control IC. Minimize any leakage current paths from SS
node, since the internal current source is only 28µA.
A multi-layer printed circuit board is recommended. Figure
8shows the connections of the critical components in the
converter. Note that the capacitors CIN and COUT each
represent numerous physical capacitors. Dedicate one
solid layer for a ground plane and make all critical
component ground connections with vias to this layer.
Dedicate another solid layer as a power plane and break
this plane into smaller islands of common voltage levels.
The power plane should support the input power and
output power nodes. Use copper filled polygons on the top
and bottom circuit layers for the PHASE nodes, but do not
unnecessarily oversize these particular islands. Since the
PHASE nodes are subjected to very high dV/dt voltages,
the stray capacitor formed between these islands and the
surrounding circuitry will tend to couple switching noise.
Use the remaining printed circuit layers for small signal
2-306
wiring. The wiring traces from the control IC to the
MOSFET gate and source should be sized to carry 2A
peak currents.
PWM Controller Feedback Compensation
The PWM controller uses voltage-mode control for output
regulation. This section highlights the design consideration
for a PWM voltage-mode controller. Apply the methods and
considerations only to the PWM controller.
Figure 9 highlights the voltage-mode control loop for a
synchronous-rectified buck converter. The output voltage
(VOUT) is regulated to the Reference voltage level. The
reference voltage level is the DAC output voltage (DACOUT).
The error amplifier (Error Amp) output (VE/A) is compared
with the oscillator (OSC) triangular wave to provide a pulsewidth modulated (PWM) wave with an amplitude of VIN at
the PHASE node. The PWM wave is smoothed by the output
filter (LO and CO).
The modulator transfer function is the small-signal transfer
function of VOUT/VE/A . This function is dominated by a DC
Gain, given by VIN/VOSC , and shaped by the output filter,
with a double pole break frequency at FLC and a zero at
FESR .
Modulator Break Frequency Equations
1
F LC = ---------------------------------------2π × L O × C O
1
F ESR = ----------------------------------------2π × ESR × C O
The compensation network consists of the error amplifier
(internal to the HIP6021) and the impedance networks ZIN
and ZFB . The goal of the compensation network is to provide
a closed loop transfer function with high 0dB crossing
frequency (f0dB) and adequate phase margin. Phase margin
is the difference between the closed loop phase at f0dB and
180 degrees. The equations below relate the compensation
network’s poles, zeros and gain to the components (R1, R2,
R3, C1, C2, and C3) in Figure 8. Use these guidelines for
locating the poles and zeros of the compensation network:
1. Pick Gain (R2/R1) for desired converter bandwidth
2. Place 1ST Zero Below Filter’s Double Pole (~75% FLC)
3. Place 2ND Zero at Filter’s Double Pole
4. Place 1ST Pole at the ESR Zero
5. Place 2ND Pole at Half the Switching Frequency
6. Check Gain against Error Amplifier’s Open-Loop Gain
7. Estimate Phase Margin - Repeat if Necessary
HIP6021
+5VIN
Compensation Break Frequency Equations
LIN
CIN
+12V
1
F Z1 = ----------------------------------2π × R 2 × C1
1
F P1 = ------------------------------------------------------C1 × C2
2π × R 2 ×  ----------------------
 C1 + C2
1
F Z2 = ------------------------------------------------------2π × ( R1 + R3 ) × C3
1
F P2 = ----------------------------------2π × R 3 × C3
CVCC
COCSET1
VCC GND
OCSET1
+3.3VIN
ROCSET1
Q3
DRIVE2
Q1
LOUT1
UGATE1
VOUT2
VOUT1
COUT1
LGATE1
SS
CSS
CR1
Q2
HIP6021
VOUT3
LOAD
LOAD
COUT2
VOUT4
COUT3
DRIVE3 DRIVE4
COUT4
PGND
Q4
LOAD
LOAD
PHASE1
Q5
+3.3VIN
KEY
ISLAND ON POWER PLANE LAYER
ISLAND ON CIRCUIT PLANE LAYER
VIA CONNECTION TO GROUND PLANE
FIGURE 8. PRINTED CIRCUIT BOARD POWER PLANES AND
ISLANDS
Figure 10 shows an asymptotic plot of the DC-DC
converter’s gain vs. frequency. The actual Modulator Gain
has a high gain peak dependent on the quality factor (Q) of
the output filter, which is not shown in Figure 9. Using the
above guidelines should yield a Compensation Gain similar
to the curve plotted. The open loop error amplifier gain
bounds the compensation gain. Check the compensation
gain at FP2 with the capabilities of the error amplifier. The
Closed Loop Gain is constructed on the log-log graph of
Figure 10 by adding the Modulator Gain (in dB) to the
Compensation Gain (in dB). This is equivalent to multiplying
the modulator transfer function to the compensation transfer
function and plotting the gain.
The compensation gain uses external impedance networks
ZFB and ZIN to provide a stable, high bandwidth (BW) overall
loop. A stable control loop has a gain crossing with
-20dB/decade slope and a phase margin greater than 45
degrees. Include worst case component variations when
determining phase margin.
FZ1
VIN
OSC
DRIVER
LO
DRIVER
+
VOUT
PHASE
CO
ESR
(PARASITIC)
ZFB
VE/A
-
ERROR
AMP
0
-40
REFERENCE
-60
DETAILED COMPENSATION COMPONENTS
C1
 V IN 
20 log  ------------
 V PP
ZFB
VOUT
COMPENSATION
GAIN
20
ZIN
C2
OPEN LOOP
ERROR AMP GAIN
40
-20
+
FP2
60
GAIN (dB)
∆ VOSC
FP1
80
PWM
COMP
-
FZ2
100
R2
20 log  --------
 R1
MODULATOR
GAIN
10
100
FLC
1K
CLOSED LOOP
GAIN
FESR
10K
100K
1M
10M
FREQUENCY (Hz)
FIGURE 10. ASYMPTOTIC BODE PLOT OF CONVERTER GAIN
ZIN
C3
R2
R3
Component Selection Guidelines
R1
COMP
Output Capacitor Selection
-
FB
+
HIP6021
DACOUT
FIGURE 9. VOLTAGE-MODE BUCK CONVERTER
COMPENSATION DESIGN
2-307
The output capacitors for each output have unique
requirements. In general, the output capacitors should be
selected to meet the dynamic regulation requirements.
Additionally, the PWM converters require an output capacitor
to filter the current ripple. The load transient for the
microprocessor core requires high quality capacitors to
supply the high slew rate (di/dt) current demands.
HIP6021
PWM Output Capacitors
Modern microprocessors produce transient load rates above
1A/ns. High frequency capacitors initially supply the
transient current and slow the load rate-of-change seen by
the bulk capacitors. The bulk filter capacitor values are
generally determined by the ESR (effective series
resistance) and voltage rating requirements rather than
actual capacitance requirements.
High frequency decoupling capacitors should be placed as
close to the power pins of the load as physically possible. Be
careful not to add inductance in the circuit board wiring that
could cancel the usefulness of these low inductance
components. Consult with the manufacturer of the load on
specific decoupling requirements.
Use only specialized low-ESR capacitors intended for
switching-regulator applications for the bulk capacitors. The
bulk capacitor’s ESR determines the output ripple voltage
and the initial voltage drop following a high slew-rate
transient’s edge. An aluminum electrolytic capacitor’s ESR
value is related to the case size with lower ESR available in
larger case sizes. However, the equivalent series inductance
(ESL) of these capacitors increases with case size and can
reduce the usefulness of the capacitor to high slew-rate
transient loading. Unfortunately, ESL is not a specified
parameter. Work with your capacitor supplier and measure
the capacitor’s impedance with frequency to select a suitable
component. In most cases, multiple electrolytic capacitors of
small case size perform better than a single large case
capacitor.
Linear Output Capacitors
The output capacitors for the linear regulators provide
dynamic load current. The linear controllers use dominant
pole compensation integrated into the error amplifier and are
insensitive to output capacitor selection. Output capacitors
should be selected for transient load regulation.
PWM Output Inductor Selection
The PWM converter requires an output inductor. The output
inductor is selected to meet the output voltage ripple
requirements and sets the converter’s response time to a
load transient. The inductor value determines the converter’s
ripple current and the ripple voltage is a function of the ripple
current. The ripple voltage and current are approximated by
the following equations:
V IN – V OUT V OUT
∆I = -------------------------------- × ---------------V IN
FS × L
∆V OUT = ∆I × ESR
Increasing the value of inductance reduces the ripple current
and voltage. However, the large inductance values increase
the converter’s response time to a load transient.
One of the parameters limiting the converter’s response to a
load transient is the time required to change the inductor
current. Given a sufficiently fast control loop design, the
2-308
HIP6021 will provide either 0% or 100% duty cycle in
response to a load transient. The response time is the time
interval required to slew the inductor current from an initial
current value to the post-transient current level. During this
interval the difference between the inductor current and the
transient current level must be supplied by the output
capacitor(s). Minimizing the response time can minimize the
output capacitance required.
The response time to a transient is different for the
application of load and the removal of load. The following
equations give the approximate response time interval for
application and removal of a transient load:
L O × I TRAN
t RISE = -------------------------------V IN – V OUT
L O × I TRAN
t FALL = ------------------------------V OUT
where: ITRAN is the transient load current step, tRISE is the
response time to the application of load, and tFALL is the
response time to the removal of load. Be sure to check both
of these equations at the minimum and maximum output
levels for the worst case response time.
Input Capacitor Selection
The important parameters for the bulk input capacitors are
the voltage rating and the RMS current rating. For reliable
operation, select bulk input capacitors with voltage and
current ratings above the maximum input voltage and largest
RMS current required by the circuit. The capacitor voltage
rating should be at least 1.25 times greater than the
maximum input voltage and a voltage rating of 1.5 times is a
conservative guideline. The RMS current rating requirement
for the input capacitor of a buck regulator is approximately
1/2 of the summation of the DC load current.
Use a mix of input bypass capacitors to control the voltage
overshoot across the MOSFETs. Use ceramic capacitance
for the high frequency decoupling and bulk capacitors to
supply the RMS current. Small ceramic capacitors can be
placed very close to the upper MOSFET to suppress the
voltage induced in the parasitic circuit impedances.
For a through-hole design, several electrolytic capacitors
(Panasonic HFQ series or Nichicon PL series or Sanyo
MV-GX or equivalent) may be needed. For surface mount
designs, solid tantalum capacitors can be used, but caution
must be exercised with regard to the capacitor surge current
rating. These capacitors must be capable of handling the
surge-current at power-up. The TPS series available from
AVX, and the 593D series from Sprague are both surge
current tested.
MOSFET Selection/Considerations
The HIP6021 requires 5 external transistors. Two N-channel
MOSFETs are used in the synchronous-rectified buck
topology of PWM1 converter. It is recommended that the
AGP linear regulator pass element be a N-channel MOSFET
as well. The GTL and memory linear controllers can also
HIP6021
each drive a MOSFET or a NPN bipolar as a pass transistor.
All these transistors should be selected based upon
rDS(ON) , current gain, saturation voltages, gate supply
requirements, and thermal management considerations.
PWM MOSFET Selection and Considerations
In high-current PWM applications, the MOSFET power
dissipation, package selection and heatsink are the
dominant design factors. The power dissipation includes two
loss components; conduction loss and switching loss. These
losses are distributed between the upper and lower
MOSFETs according to duty factor (see the equations
below). The conduction losses are the main component of
power dissipation for the lower MOSFETs. Only the upper
MOSFET has significant switching losses, since the lower
device turns on and off into near zero voltage.
The equations below assume linear voltage-current
transitions and do not model power loss due to the reverserecovery of the lower MOSFET’s body diode. The gatecharge losses are dissipated by the HIP6021 and don't heat
the MOSFETs. However, large gate-charge increases the
switching time, tSW which increases the upper MOSFET
switching losses. Ensure that both MOSFETs are within their
maximum junction temperature at high ambient temperature
by calculating the temperature rise according to package
thermal-resistance specifications. A separate heatsink may
be necessary depending upon MOSFET power, package
type, ambient temperature and air flow.
2
I O × r DS ( ON ) × V OUT I O × V IN × t SW × F S
P UPPER = ------------------------------------------------------------ + ---------------------------------------------------V IN
2
2
I O × r DS ( ON ) × ( V IN – V OUT )
P LOWER = --------------------------------------------------------------------------------V IN
The rDS(ON) is different for the two equations above even if
the same device is used for both. This is because the gate
drive applied to the upper MOSFET is different than the
lower MOSFET. Figure 11 shows the gate drive where the
upper MOSFET’s gate-to-source voltage is approximately
VCC less the input supply. For +5V main power and +12VDC
for the bias, the gate-to-source voltage of Q1 is 7V. The
lower gate drive voltage is +12VDC. A logic-level MOSFET is
a good choice for Q1 and a logic-level MOSFET can be used
for Q2 if its absolute gate-to-source voltage rating exceeds
the maximum voltage applied to VCC.
Rectifier CR1 is a clamp that catches the negative inductor
swing during the dead time between the turn off of the lower
MOSFET and the turn on of the upper MOSFET. The diode
must be a Schottky type to prevent the lossy parasitic
MOSFET body diode from conducting. It is acceptable to
omit the diode and let the body diode of the lower MOSFET
clamp the negative inductor swing, but efficiency could drop
one or two percent as a result. The diode's rated reverse
breakdown voltage must be greater than the maximum input
voltage.
2-309
+5V OR LESS
+12V
VCC
HIP6021
UGATE
Q1
PHASE
-
LGATE
NOTE:
VGS ≈ VCC -5V
Q2
CR1
+
PGND
NOTE:
VGS ≈ VCC
GND
FIGURE 11. UPPER GATE DRIVE - DIRECT VCC DRIVE OPTION
Linear Controller Transistor Selection
The main criteria for selection of transistors for the linear
regulators is package selection for efficient removal of heat.
The power dissipated in a linear regulator is:
P LINEAR = I O × ( V IN – V OUT )
Select a package and heatsink that maintains the junction
temperature below the rating with a the maximum expected
ambient temperature.
When selecting bipolar NPN transistors for use with the
linear controllers, insure the current gain at the given
operating VCE is sufficiently large to provide the desired
output load current when the base is fed with the minimum
driver output current.
HIP6021
HIP6021 DC-DC Converter Application Circuit
For detailed information on the circuit, including a Bill-ofMaterials and circuit board description, see Application Note
AN9836. Also see Intersil’s web page (http://www.intersil.com)
or Intersil AnswerFAX (407-724-7800) Document No. 99836 for
the latest information.
Figure 12 shows an application circuit of a power supply for a
microprocessor computer system. The power supply provides
the microprocessor core voltage (VOUT1), the AGP bus
voltage (VOUT2), the GTL bus voltage (VOUT3), and the
memory voltage (VOUT4) from +3.3V, +5VDC, and +12VDC.
+12VIN
L1
+5VIN
1µH
C1-6 +
6x1000µF
GND
C7
1µF
C8
1000pF
C9
1µF
VCC
28
FAULT/RT
R1
23
OCSET
13
1.0K
POWERGOOD
+3.3VIN
VAUX
DRIVE2
8
16
PGOOD
Q1,2
2xHUF76143S3S
27 UGATE
1
VOUT2
26
(3.3V or 1.5V)
+
C10,11
2x1000µF
VSEN2
Q3
HUF76121D3S
4.2µH
25
SELECT
11
22
U1
C12-19 +
8x1000µF
LGATE
21
R2
10.2K
VSEN1
FB
HIP6021
Q4
HUF76107D3S
DRIVE3
VOUT3
(1.5V)
VSEN3
+
18
20
COMP
C22
2.7nF
7
VOUT4
DRIVE4
VSEN4
(1.8V)
+
C25,26
2x1000µF
SD
FIX
R3
1.62k
C21
10pF
C20
0.22µF
19
C23,24
2x1000µF
Q5
HUF76107D3S
VOUT1
(1.3V-3.5V)
PHASE
10
24 PGND
TYPEDET
L2
VID0
R4
150K
R5
499K
6 VID1
VID2
5
4 VID3
15
14
3
VID4
12 SS
9
2
17
C27
0.1µF
GND
FIGURE 12. POWER SUPPLY APPLICATION CIRCUIT FOR A MICROPROCESSOR COMPUTER SYSTEM
All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.
Intersil semiconductor products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see web site http://www.intersil.com
2-310