INTERSIL HIP6019BCB

HIP6019B
®
Data Sheet
April 13, 2005
Advanced Dual PWM and Dual Linear
Power Control
Features
The HIP6019B provides the power control and protection for
four output voltages in high-performance microprocessor and
computer applications. The IC integrates two PWM
controllers, a linear regulator and a linear controller as well as
the monitoring and protection functions into a single 28 lead
SOIC package. One PWM controller regulates the
microprocessor core voltage with a synchronous-rectified
buck converter, while the second PWM controller supplies the
computer’s 3.3V power with a standard buck converter. The
linear controller regulates power for the GTL bus and the
linear regulator provides power for the clock driver circuits.
The HIP6019B includes an Intel-compatible, TTL 5-input
digital-to-analog converter (DAC) that adjusts the core PWM
output voltage from 2.1VDC to 3.5VDC in 0.1V increments
and from 1.3VDC to 2.05VDC in 0.05V steps. The precision
reference and voltage-mode control provide ±1% static
regulation. The second PWM controller is user-adjustable for
output levels between 3.0V and 3.5V with ±2% accuracy. The
adjustable linear regulator uses an internal pass device to
provide 2.5V ±2.5%. The adjustable linear controller drives an
external N-Channel MOSFET to provide 1.5V ±2.5%.
The HIP6019B monitors all the output voltages. A single
Power Good signal is issued when the core is within ±10% of
the DAC setting and the other levels 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 functions monitor the output current
by sensing the voltage drop across the upper MOSFET’s
rDS(ON), eliminating the need for a current sensing resistor.
Pinout
HIP6019B
(SOIC)
TOP VIEW
FN4587.1
• Provides 4 Regulated Voltages
- Microprocessor Core, I/O, Clock Chip and GTL Bus
• Drives N-Channel MOSFETs
• Operates from +5V and +12V Inputs
• Simple Single-Loop Control Designs
- Voltage-Mode PWM Control
• Fast Transient Response
- High-Bandwidth Error Amplifiers
- Full 0% to 100% Duty Ratios
• Excellent Output Voltage Regulation
- Core PWM Output: ±1% Over Temperature
- I/O PWM Output: ±2% Over Temperature
- Other Outputs: ±2.5% Over Temperature
• TTL-Compatible 5-Bit Digital-to-Analog Core Output
Voltage Selection
- Wide Range . . . . . . . . . . . . . . . . . . . 1.3VDC to 3.5VDC
- 0.1V Steps . . . . . . . . . . . . . . . . . . . . 2.1VDC to 3.5VDC
- 0.05V Steps . . . . . . . . . . . . . . . . . . 1.3VDC to 2.05VDC
• Power-Good Output Voltage Monitor
• Microprocessor Core Voltage Protection Against Shorted
MOSFET
• Over-Voltage and Over-Current Fault Monitors
- 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 1MHz
• Pb-Free Available (RoHS Compliant)
UGATE2 1
28 VCC
PHASE2 2
27 UGATE1
VID4 3
26 PHASE1
• Full Motherboard Power Regulation for Computers
VID3 4
25 LGATE1
• Low-Voltage Distributed Power Supplies
VID2 5
24 PGND
VID1 6
23 OCSET1
VID0 7
22 VSEN1
PGOOD 8
21 FB1
OCSET2 9
20 COMP1
19 FB3
FB2 10
18 GATE3
COMP2 11
17 GND
SS 12
FAULT/RT 13
16 VOUT4
FB4 14
15 VSEN2
1
Applications
Ordering Information
PART NUMBER
TEMP. (oC)
PACKAGE
PKG. DWG. #
HIP6019BCB
0 to 70
28 Ld SOIC
M28.3
HIP6019BCBZ
(See Note)
0 to 70
28 Ld SOIC
(Pb-free)
M28.3
Add “-T” suffix for tape and reel.
NOTE: Intersil Pb-free products employ special Pb-free material sets; molding
compounds/die attach materials and 100% matte tin plate termination finish, which are
RoHS compliant and compatible with both SnPb and Pb-free soldering operations.
Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that
meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-352-6832 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 1998, 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
VSEN2
FB2
COMP2
PHASE2
GATE2
FB4
VOUT4
GATE3
2.5V
VCC
0.25A
VSEN2
+
-
+
-
+
-
+
4.3V
-
+
-
+
0.3V
-
INHIBIT
+
+
-
PWM
COMP2
PWM2
1.26V
+
1.26V
GATE
CONTROL
DRIVE2
-
+
+
-
-
+
-
+
-
+
ERROR
AMP2
-
2
+
FB3
FAULT / RT
LUV
4V
11µA
FIGURE 1.
SS
OV
VCC
SOFTSTART
AND FAULT
LOGIC
OC
FAULT
200µA
OSCILLATOR
OC2
OC4
LINEAR
UNDERVOLTAGE
OCSET2
DACOUT
-
+
-
+
-
+
-
+
OC1
COMP1
ERROR
AMP1
FB1
115%
90%
110%
VSEN1
PWM1
DRIVE1
RESET (POR)
POWER-ON
VCC
VID4
VID0
VID2
VID1
VID3
LOWER
DRIVE
GATE
CONTROL
INHIBIT
TTL D/A
CONVERTER
(DAC)
PWM
COMP1
-
+
-
+
200µA
OCSET1
VCC
VCC
GND
PGND
LGATE1
PHASE1
UGATE1
PGOOD
HIP6019B
Block Diagram
FN4587.1
April 13, 2005
HIP6019B
Simplified Power System Diagram
+5VIN
PWM2
CONTROLLER
VOUT1
PWM1
CONTROLLER
VOUT2
HIP6019B
LINEAR
CONTROLLER
VOUT3
LINEAR
REGULATOR
VOUT4
FIGURE 2.
Typical Application
+12VIN
+5VIN
CIN
VCC
OCSET2
OCSET1
POWERGOOD
PGOOD
VOUT2
Q3
LOUT2
3.0V TO 3.5V
COUT2
UGATE2
UGATE1
PHASE2
PHASE1
CR2
Q1
Q2
LGATE1
FB2
VOUT1
1.3V TO 3.5V
COUT1
CR1
PGND
VSEN2
LOUT1
VSEN1
HIP6019B
COMP2
FB1
COMP1
FAULT / RT
Q4
VID0
GATE3
VOUT3
1.5V
VID1
FB3
VID2
VID3
COUT3
VID4
VOUT4
2.5V
SS
VOUT4
CSS
FB4
COUT4
GND
FIGURE 3.
3
FN4587.1
April 13, 2005
HIP6019B
Absolute Maximum Ratings
Thermal Information
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+15V
PGOOD, RT/FAULT, and GATE Voltage . . GND - 0.3V to VCC + 0.3V
Input, Output or I/O Voltage . . . . . . . . . . . . . . . . . . GND -0.3V to 7V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 2
Thermal Resistance (Typical, Note 1)
Operating Conditions
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . +12V ±10%
Ambient Temperature Range. . . . . . . . . . . . . . . . . . . . . 0oC to 70oC
Junction Temperature Range . . . . . . . . . . . . . . . . . . . 0oC to 125oC
θJA (oC/W)
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . .
60
50
SOIC Package (with 3 in2 of copper) . . . . . . . . . . .
Maximum Junction Temperature (Plastic Package) . . . . . . . .150oC
Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC
(SOIC - Lead Tips Only)
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 Figures 1, 2 and 3
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
-
10
-
mA
VCC SUPPLY CURRENT
Nominal Supply
ICC
UGATE1, GATE2, GATE3, LGATE1, and
VOUT4 Open
POWER-ON RESET
Rising VCC Threshold
VOCSET = 4.5V
8.6
-
10.4
V
Falling VCC Threshold
VOCSET = 4.5V
8.2
-
10.2
V
-
1.25
-
V
Rising VOCSET1 Threshold
OSCILLATOR
Free Running Frequency
RT = OPEN
185
200
215
kHz
Total Variation
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
%
1.240
1.265
1.290
V
-2.5
-
2.5
%
-
75
87
%
-
6
-
%
180
230
-
mA
CSS Voltage < 4V
560
700
-
mA
VSEN3 = GATE3
-2.5
-
2.5
%
-
75
87
%
-
6
-
%
∆VOSC
Ramp Amplitude
RT = Open
REFERENCE AND DAC
Reference Voltage
(Pin FB2, FB3, and FB4)
LINEAR REGULATOR
Regulation
10mA < IVOUT4 < 150mA
Under-Voltage Level
FB4UV
FB4 Rising
Under-Voltage Hysteresis
Over-Current Protection
Over-Current Protection During Start-Up
LINEAR CONTROLLER
Regulation
Under-Voltage Level
FB3UV
Under-Voltage Hysteresis
4
FB3 Rising
FN4587.1
April 13, 2005
HIP6019B
Electrical Specifications
Recommended Operating Conditions, Unless Otherwise Noted.
Refer to Figures 1, 2 and 3 (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
-
88
-
dB
-
15
-
MHz
COMP = 10pF
-
6
-
V/µs
PWM CONTROLLER ERROR AMPLIFIERS
DC Gain
Gain-Bandwidth Product
GBWP
Slew Rate
SR
PWM CONTROLLER GATE DRIVERS
Drive1 (and 2) Source
IUGATE
VCC = 12V, VUGATE1 (or VGATE2) = 6V
-
1
-
A
Drive1 (and 2) Sink
RUGATE
VGATE-PHASE = 1V
-
1.7
3.5
Ω
Lower Gate Source
ILGATE
VCC = 12V, VLGATE = 1V
-
1
-
A
Lower Gate Sink
RLGATE
VGATE = 1V
-
1.4
3.0
Ω
PROTECTION
VOUT1 Over-Voltage Trip
VSEN1 Rising
112
115
118
%
VOUT2 Over-Voltage Trip
VSEN2 Rising
4.1
4.3
4.5
V
-
70
-
kΩ
VSEN2 Input Resistance
FAULT Sourcing Current
OCSET1(and 2) Current Source
IOVP
VFAULT/RT = 10.0V
10
14
-
mA
IOCSET
VOCSET = 4.5VDC
170
200
230
µA
-
11
-
µA
-
-
1.0
V
Soft-Start Current
ISS
Chip Shutdown Soft-Start Threshold
POWER GOOD
VOUT1 Upper Threshold
VSEN1 Rising
108
-
110
%
VOUT1 Under-Voltage
VSEN1 Rising
92
-
94
%
VOUT1 Hysteresis
Upper/Lower Threshold
-
2
-
%
VOUT2 Under-Voltage
VSEN2 Rising
2.45
2.55
2.65
V
-
100
-
mV
-
-
0.5
V
VOUT2 Under-Voltage Hysteresis
PGOOD Voltage Low
VPGOOD
IPGOOD = -4mA
Typical Performance Curves
140
120
RT PULLUP
TO +12V
CGATE = 4800pF
100
ICC (mA)
RESISTANCE (kΩ)
1000
CUGATE1 = CUGATE2 = CLGATE1 = CGATE
VVCC = 12V, VIN = 5V
100
80
CGATE = 3600pF
60
CGATE = 1500pF
40
10
CGATE = 660pF
RT PULLDOWN TO VSS
10
100
SWITCHING FREQUENCY (kHz)
FIGURE 4. RT RESISTANCE vs FREQUENCY
5
20
1000
100
200
300
400
500
600
700
800
900
1000
SWITCHING FREQUENCY (kHz)
FIGURE 5. BIAS SUPPLY CURRENT vs FREQUENCY
FN4587.1
April 13, 2005
HIP6019B
Functional Pin Description
VSEN1, VSEN2 (Pins 22 and 15)
These pins are connected to the PWM converters’ output
voltages. The PGOOD and OVP comparator circuits use
these signals to report output voltage status and for overvoltage protection. VSEN2 provides the input power to the
integrated linear regulator.
OCSET1, OCSET2 (Pins 23 and 9)
Connect a resistor (ROCSET) from this pin to the drain of the
respective upper MOSFET. ROCSET, an internal 200µA
current source (IOCSET), and the upper MOSFET onresistance (rDS(ON)) set the converter over-current (OC) trip
point according to the following equation:
I OCSET × R OCSET
I PEAK = --------------------------------------------------r DS ( ON )
An over-current trip cycles the soft-start function. Sustaining an
over-current for 2 soft-start intervals shuts down the controller.
PHASE1, PHASE2 (Pins 26 and 2)
Connect the PHASE pins to the respective PWM converter’s
upper MOSFET source. These pins are used to monitor the
voltage drop across the upper MOSFETs for over-current
protection.
UGATE1, UGATE2 (Pins 27 and 1)
Connect UGATE pins to the respective PWM converter’s
upper MOSFET gate. These pins provide the gate drive for
the upper MOSFETs.
PGND (Pin 24)
This is the power ground connection. Tie the synchronous
PWM converter’s lower MOSFET source to this pin.
LGATE1 (Pin 25)
Connect LGATE1 to the synchronous PWM converter’s
lower MOSFET gate. This pin provides the gate drive for the
lower MOSFET.
VCC (Pin 28)
Additionally, OCSET1 is an output for the inverted FAULT
signal (FAULT). If a fault condition causes FAULT to go high,
OCSET1 will be simultaneously pulled to ground though an
internal MOS device (typical rDS(ON) = 100Ω).
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.
SS (Pin 12)
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:
Connect a capacitor from this pin to ground. This capacitor,
along with an internal 11µA current source, sets the softstart interval of the converter. Pulling this pin low (typically
below 1.0V) with an open drain signal will shutdown the IC.
VID0, VID1, VID2, VID3, VID4 (Pins 7, 6, 5, 4 and 3)
VID0-4 are the input pins to the 5-bit DAC. The states of
these five pins program the internal voltage reference
(DACOUT). The level of DACOUT sets the core converter
output voltage (VOUT1). It also sets the core PGOOD and
OVP thresholds.
COMP1, COMP2, and FB1, FB2
(Pins 20, 11, 21, and 10)
COMP1, 2 and FB1, 2 are the available external pins of the
PWM error amplifiers. Both the FB pins are the inverting
input of the error amplifiers. Similarly, the COMP pins are the
error amplifier outputs. These pins are used to compensate
the voltage-control feedback loops of the PWM converters.
GND (Pin 17)
Signal ground for the IC. All voltage levels are measured
with respect to this pin.
PGOOD (Pin 8)
PGOOD is an open collector output used to indicate the
status of the PWM converter output voltages. This pin is
pulled low when the core output is not within ±10% of the
DACOUT reference voltage, or when any of the other
outputs are below their under-voltage thresholds. The
PGOOD output is open for ‘11111’ VID code. See Table 1.
6
FAULT/RT (Pin 13)
6
5 × 10
Fs ≈ 200kHz + --------------------R T ( kΩ )
(RT to GND)
Conversely, connecting a pull-up resistor (RT) 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, this pin voltage is 1.26V, but is pulled to VCC in
the event of an over-voltage or over-current condition.
GATE3 (Pin 18)
Connect this pin to the gate of an external MOSFET. This
pin provides the drive for the linear controller’s pass
transistor.
FB3 (Pin 19)
Connect this pin to a resistor divider to set the linear
controller output.
VOUT4 (Pin 16)
Output of the linear regulator. Supplies current up to 230mA.
FB4 (Pin 14)
Connect this pin to a resistor divider to set the linear
regulator output.
FN4587.1
April 13, 2005
HIP6019B
Description
Operation
The HIP6019B monitors and precisely controls 4 output
voltage levels (Refer to Figures 1, 2, and 3). It is designed
for microprocessor computer applications with 5V power and
12V bias input from a PS2 or ATX power supply. The IC has
2 PWM controllers, a linear controller, and a linear regulator.
The first PWM controller (PWM1) is designed to regulate the
microprocessor core voltage (VOUT1). PWM1 controller
drives 2 MOSFETs (Q1 and Q2) in a synchronous-rectified
buck converter configuration and regulates the core voltage
to a level programmed by the 5-bit digital-to-analog
converter (DAC). The second PWM controller (PWM2) is
designed to regulate the I/O voltage (VOUT2). PWM2
controller drives a MOSFET (Q3) in a standard buck
converter configuration and regulates the I/O voltage to a
resistor programmable level between 3.0 and 3.5VDC. An
integrated linear regulator supplies the 2.5V clock generator
power (VOUT4). The linear controller drives an external
MOSFET (Q4) to supply the GTL bus power (VOUT3).
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 3.3V output (VOUT2) in
Figure 6, 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 to 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.
PGOOD
(2V/DIV)
0V
SOFT-START
(1V/DIV)
VOUT2 ( = 3.3V)
0V
Initialization
The HIP6019B 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 and the 5V input
voltage (+5VIN) at the OCSET1 pin. The normal level on
OCSET1 is equal to +5VIN less a fixed voltage drop (see
over-current protection). The POR function initiates soft-start
operation after both input supply voltages exceed their POR
thresholds.
VOUT4 ( = 2.5V)
VOUT1 (DAC = 2V)
OUTPUT
VOLTAGES
(0.5V/DIV)
VOUT3 ( = 1.5V)
0V
T0 T1
Soft-Start
T2
T3
TIME
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
11µA current source charges an external capacitor (CSS) on
the SS pin to 4V. The PWM error amplifier reference inputs
(+ terminal) and outputs (COMP1 and COMP2 pins) are
clamped to a level proportional to the SS pin voltage. As the
SS pin voltage ramps from 1V to 4V, the output clamp allows
generation of PHASE pulses of increasing width that charge
the output capacitor(s). After this initial stage, the reference
input clamp slows the output voltage rate-of-rise and
provides a smooth transition to the final set voltage.
Additionally, both linear regulator’s reference inputs are
clamped to a voltage proportional to the SS pin voltage. This
method provides a rapid and controlled output voltage rise.
Figure 6 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 waveform is compared to the clamped
error amplifier output voltage. As the SS pin voltage
7
FIGURE 6. SOFT-START INTERVAL
The remaining outputs are also programmed to follow the
SS pin voltage. Each linear output (VOUT3 and VOUT4)
initially follows the 3.3V output (VOUT2). When each output
reaches sufficient voltage the input reference clamp slows
the rate of output voltage rise. The PGOOD signal toggles
‘high’ when all output voltage levels have exceeded their
under-voltage levels. See the Soft-Start Interval section
under 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 linear regulator
output or an over-voltage on the PWM outputs disables all
converters and drives the FAULT/RT pin to VCC.
Figure 7 shows a simplified schematic of the fault logic. An
over-voltage detected on either VSEN1 or VSEN2
immediately sets the fault latch. A sequence of three overcurrent fault signals also sets the fault latch. A comparator
FN4587.1
April 13, 2005
HIP6019B
indicates when CSS is fully charged (UP signal), such that an
under-voltage event on either linear output (FB3 or FB4) is
ignored until after the soft-start interval (approximately T3 in
Figure 6). At start-up, this allows VOUT3 and VOUT4 to slew
up over increased time intervals, without generating a fault.
Cycling the bias input voltage (+12VIN on the VCC pin) off
then on resets the counter and the fault latch.
LUV
OC1
INHIBIT
OC2
S
R
0.15V
+
-
COUNTER
R
SS
4V
+
-
FAULT/RT
S Q
FAULT
LATCH
S Q
UP
R
POR
FAULT
OV
FIGURE 7. FAULT LOGIC - SIMPLIFIED SCHEMATIC
Over-Voltage Protection
During operation, a short on the upper MOSFET (Q1)
causes VOUT1 to increase. When the output exceeds the
over-voltage threshold of 115% of DACOUT, the overvoltage comparator trips to set the fault latch and turns Q2
on as required in order to regulate VOUT1 to 1.15 x
DACOUT. This blows the input fuse and reduces VOUT1.
The fault latch raises the FAULT/RT pin close to VCC
potential.
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), VOUT1 is
monitored for voltages exceeding 1.26V. Should VSEN1
exceed this level, the lower MOSFET (Q2) is driven on, as
needed to regulate VOUT1 to 1.26V.
Over-Current Protection
FAULT
REPORTED
10V
0V
VCC
INDUCTOR CURRENT SOFT-START
OVER
CURRENT
LATCH
counter. CSS recharges at T2 and initiates a soft-start cycle
with the error amplifiers clamped by soft-start. With OUT2 still
overloaded, the inductor current increases to trip the overcurrent 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.
COUNT
=1
COUNT
=2
COUNT
=3
4V
2V
0V
OVERLOAD
APPLIED
0A
T0 T1
T2
T3
T4
TIME
FIGURE 8. OVER-CURRENT OPERATION
The PWM1 controller and the linear regulator operate in the
same way as PWM2 to over-current faults. Additionally, the
linear regulator and linear controller monitor the feedback
pins for an under-voltage. Should excessive currents cause
FB3 or FB4 to fall below the linear under-voltage 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 undervoltage threshold during normal start-up. Cycling the bias
input power off then on resets the counter and the fault latch.
All outputs are protected against excessive over-currents.
Both PWM controllers use the upper MOSFET’s
on-resistance, rDS(ON) to monitor the current for protection
against shorted outputs. The linear regulator monitors the
current of the integrated power device and signals an overcurrent condition for currents in excess of 230mA.
Additionally, both the linear regulator and the linear
controller monitor FB3 and FB4 for under-voltage to protect
against excessive currents.
Figures 8 and 9 illustrate the over-current protection with an
overload on OUT2. The overload is applied at T0 and the
current increases through the output inductor (LOUT2). At time
T1, the OVER-CURRENT2 comparator trips when the voltage
across Q3 (ID • rDS(ON)) exceeds the level programmed by
ROCSET. This inhibits all outputs, discharges the soft-start
capacitor (CSS) with a 11µA current sink, and increments the
8
FN4587.1
April 13, 2005
HIP6019B
OVER-CURRENT TRIP: VDS > VSET
VIN = +5V
(ID • rDS(ON) > IOCSET • ROCSET)
OCSET
IOCSET
200µA
ROCSET
Application Guidelines
VSET +
ID
Soft-Start Interval
VCC
DRIVE
OC2
+
UGATE
+
VDS
PHASE
-
OVERCURRENT2
PWM
VPHASE = VIN - VDS
VOCSET = VIN - VSET
GATE
CONTROL
the PGOOD signal and exercise the over-voltage protection.
The ‘11111’ VID pin combination resulting in an INHIBIT
disables the IC and the open-collector at the PGOOD pin.
HIP6019B
FIGURE 9. OVER-CURRENT DETECTION
Resistors (ROCSET1 and ROCSET2) program the overcurrent trip levels for each PWM converter. As shown in
Figure 9, the internal 200µA current sink develops a voltage
across ROCSET (VSET) that is referenced to VIN. The DRIVE
signal enables the over-current comparator (OVERCURRENT1 or OVER-CURRENT2). When the voltage
across the upper MOSFET (VDS) exceeds VSET, the overcurrent 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:
Initially, the soft-start function clamps the error amplifiers’
output of the PWM converters. After the output voltage
increases to approximately 80% 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
voltage sequence is shown in Figure 6.
The soft-start function controls the output voltage rate of rise
to limit the current surge at start-up. The soft-start interval is
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 80% of the set value.
Shutdown
Neither PWM output switches until the soft-start voltage
(VSS) exceeds the oscillator’s valley voltage. Additionally,
the reference on each linear’s amplifier is 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 resulting in an INHIBIT as shown in
Table 1 also shuts down the IC.
I OCSET × R OCSET
I PEAK = --------------------------------------------------------r DS ( ON )
TABLE 1.
PIN NAME
The OC trip point varies with MOSFET’s temperature. To avoid
over-current tripping in the normal operating load range,
determine the ROCSET resistor from the equation above with:
VID4
VID3
VID2
VID1
VID0
NOMINAL
OUT1
VOLTAGE
DACOUT
0
1
1
1
1
1.30
1. The maximum rDS(ON) at the highest junction temperature.
0
1
1
1
0
1.35
2. The minimum IOCSET from the specification table.
0
1
1
0
1
1.40
3. Determine IPEAK for IPEAK > IOUT(MAX) + (∆I)/2,
where ∆I is the output inductor ripple current.
0
1
1
0
0
1.45
0
1
0
1
1
1.50
For an equation for the output inductor ripple current see the
section under component guidelines titled ‘Output Inductor
Selection’.
0
1
0
1
0
1.55
0
1
0
0
1
1.60
0
1
0
0
0
1.65
OUT1 Voltage Program
0
0
1
1
1
1.70
The output voltage of the PWM1 converter is programmed to
discrete levels between 1.3VDC and 3.5VDC . This output is
designed to supply the microprocessor core voltage. The
voltage identification (VID) pins program an internal voltage
reference (DACOUT) through a TTL-compatible 5-bit digital-toanalog 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 +5V by a 10µA current source. Changing
the VID inputs during operation is not recommended. The
sudden change in the resulting reference voltage could toggle
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
INHIBIT
1
1
1
1
0
2.1
1
1
1
0
1
2.2
9
FN4587.1
April 13, 2005
HIP6019B
VID2
VID1
VID0
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
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 or VSS, 1 = open or connected to 5V
through pull-up resistors.
+5VIN
CIN
+12V
COCSET2
ROCSET2
Q3
LOUT2
VOUT2
CVCC
COCSET1
VCC GND
OCSET2
OCSET1
R
UGATE2
OCSET1
Q1
UGATE1
LOUT1
PHASE2
VOUT1
PHASE1
COUT2
Q4
VOUT3
HIP6019B
LGATE1
GATE3
SS
Q2
COUT1
LOAD
VID3
1
capacitors between the MOSFETs and the load. Locate the
PWM controller close to the MOSFETs.
CR1
PGND
CSS
LOAD
VID4
NOMINAL
OUT1
VOLTAGE
DACOUT
LOAD
TABLE 1.
PIN NAME
KEY
ISLAND ON POWER PLANE LAYER
ISLAND ON CIRCUIT PLANE LAYER
VIA CONNECTION TO GROUND PLANE
FIGURE 10. PRINTED CIRCUIT BOARD POWER PLANES AND
ISLANDS
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 MOSFET. Prior to turnoff, the upper
MOSFET was carrying the full load current. During the
turnoff, 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. Contact Intersil 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 HIP6019B controller. The power components are the
most critical because they switch large amounts of energy. The
critical small signal components connect to sensitive nodes or
supply critical bypassing current.
The power components should be placed first. Locate the
input capacitors close to the power switches. Minimize the
length of the connections between the input capacitors and
the power switches. Locate the output inductor and output
10
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 because the internal current source is only 11µA.
A multi-layer printed circuit board is recommended. Figure 10
shows the connections of the critical components in the
converter. Note that capacitors CIN and COUT could 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. Use the remaining printed circuit layers for
small signal wiring. The wiring traces from the control IC to the
MOSFET gate and source should be sized to carry 1A
currents. The traces for OUT4 need only be sized for 0.2A.
Locate COUT4 close to the HIP6019B IC.
PWM Controller Feedback Compensation
Both PWM controllers use voltage-mode control for output
regulation. This section highlights the design consideration
for a voltage-mode controller. Apply the methods and
considerations to both PWM controllers.
Figure 11 highlights the voltage-mode control loop for a
synchronous-rectified buck converter. The output voltage is
regulated to the reference voltage level. The reference
voltage level is the DAC output voltage for PWM1 and is
1.265V for PWM2. The error amplifier output (VE /A) is
FN4587.1
April 13, 2005
HIP6019B
compared with the oscillator (OSC) triangular wave to
provide a pulse-width modulated wave with an amplitude of
VIN at the PHASE node. The PWM wave is smoothed by
the output filter (LO and CO).
VIN
OSC
∆ VOSC
PWM
COMP
DRIVER
VOUT
ESR
(PARASITIC)
ZFB
VE/A
ERROR
AMP
ZIN
+
REFERENCE
DETAILED FEEDBACK COMPENSATION
ZFB
VOUT
C2
C1
ZIN
C3
R2
R3
R1
COMP
-
FB
+
5. Place 2ND Pole at half the switching frequency.
Compensation Break Frequency Equations
PHASE
CO
-
4. Place 1ST Pole at the ESR Zero.
7. Estimate Phase Margin - repeat if necessary.
LO
-
3. Place 2ND Zero at filter’s Double Pole.
6. Check Gain against Error Amplifier’s Open-Loop Gain.
DRIVER
+
2. Place 1ST Zero below filter’s Double Pole (~75% FLC).
HIP6019B
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
Figure 12 shows an asymptotic plot of the DC-DC
converter’s gain vs frequency. The actual modulator gain
has a peak due to the high Q factor of the output filter at FLC,
which is not shown in Figure 12. 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 12 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.
REFERENCE
100
FIGURE 11. VOLTAGE-MODE BUCK CONVERTER
COMPENSATION DESIGN
Modulator Break Frequency Equations
1
F LC = ---------------------------------------2π × L O × C O
1
F ESR = ----------------------------------------2π × ESR × C O
FP1
FP2
OPEN LOOP
ERROR AMP GAIN
60
GAIN (dB)
The modulator transfer function is the small-signal transfer
function of VOUT/VE/A. This function is dominated by a DC
gain and the output filter, with a double pole break frequency
at FLC and a zero at FESR. The DC gain of the modulator is
simply the input voltage, VIN, divided by the peak-to-peak
oscillator voltage, ∆VOSC .
FZ1 FZ2
80
40
20
20LOG
(R2/R1)
0
20LOG
(VIN/∆VOSC)
MODULATOR
GAIN
-20
COMPENSATION
GAIN
CLOSED LOOP
GAIN
-40
FLC
-60
10
100
1K
FESR
10K
100K
1M
10M
FREQUENCY (Hz)
The compensation network consists of the error amplifier
internal to the HIP6019B and the impedance networks ZIN
and ZFB . The goal of the compensation network is to
provide a closed loop transfer function with an acceptable
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 11.
Use these guidelines for locating the poles and zeros of the
compensation network:
1. Pick Gain (R2/R1) for desired converter bandwidth.
11
FIGURE 12. ASYMPTOTIC BODE PLOT OF CONVERTER GAIN
The compensation gain uses external impedance networks
ZFB and ZIN to provide a stable, high bandwidth loop. A
stable control loop has a 0dB gain crossing with
-20dB/decade slope and a phase margin greater than 45
degrees. Include worst case component variations when
determining phase margin.
Oscillator Synchronization
The PWM controllers use a triangle wave for comparison with
the error amplifier output to provide a pulse-width modulated
wave. Should the output voltages of the two PWM converters
FN4587.1
April 13, 2005
HIP6019B
be programmed close to each other, then cross-talk could
cause nonuniform PHASE pulse-widths and increased output
voltage ripple. The HIP6019B avoids this problem by
synchronizing the two converters 180o out-of-phase for DAC
settings above, and including 2.5V. This is accomplished by
inverting the triangle wave sent to PWM 2.
The output capacitors for the linear regulator and the linear
controller provide dynamic load current. The linear controller
uses dominant pole compensation integrated in the error
amplifier and is insensitive to output capacitor selection.
Capacitor, COUT3 should be selected for transient load
regulation.
Component Selection Guidelines
The output capacitor for the linear regulator provides loop
stability. The linear regulator (OUT4) requires an output
capacitor characteristic shown in Figure 13 The upper line
plots the 45 phase margin with 150mA load and the lower
line is the 45 phase margin limit with a 10mA load. Select a
COUT4 capacitor with characteristic between the two limits.
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 linear regulator is
internally compensated and requires an output capacitor that
meets the stability requirements. The load transient for the
microprocessor core requires high quality capacitors to
supply the high slew rate (di/dt) current demands.
PWM Output Capacitors
Modern microprocessors produce transient load rates above
10A/ns. High frequency capacitors initially supply the transient
and slow the current load rate seen by the bulk capacitors.
The bulk filter capacitor values are generally determined by
the ESR (effective series resistance) and ESL (effective
series inductance) parameters rather than actual capacitance.
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 after a high slew-rate transient. 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 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 suitable components. In most cases,
multiple electrolytic capacitors of small case size perform
better than a single large case capacitor. For a given transient
load magnitude, the output voltage transient response due to
the output capacitor characteristics can be approximated by
the following equation:
dI TRAN
V TRAN = ESL × --------------------- + ESR × I TRAN
dt
Linear Output Capacitors
12
0.7
0.6
0.5
ESR (Ω)
Output Capacitor Selection
0.4
LE N
A B IO
S T RAT
E
OP
0.3
0.2
0.1
10
100
CAPACITANCE (µF)
1000
FIGURE 13. COUT4 OUTPUT CAPACITOR
Output Inductor Selection
Each 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 = -------------------------------- × ---------------FS × LO
V IN
∆V OUT = ∆I × ESR
Increasing the value of inductance reduces the ripple current
and voltage. However, the large inductance values reduce
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
HIP6019B 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
capacitors. Minimizing the response time can minimize the
output capacitance required.
FN4587.1
April 13, 2005
HIP6019B
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. With a +5V input
source, the worst case response time can be either at the
application or removal of load and dependent upon the
output voltage setting. 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 capacitor are the
voltage rating and the RMS current rating. For reliable
operation, select the bulk capacitor 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.
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 should 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 MVGX 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 HIP6019B requires 4 N-Channel power MOSFETs. Two
MOSFETs are used in the synchronous-rectified buck
topology of PWM1 converter. PWM2 converter uses a
MOSFET as the buck switch and the linear controller drives
a MOSFET as a pass transistor. These should be selected
based upon rDS(ON) , gate supply requirements, and thermal
management requirements.
losses are distributed between the upper and lower
MOSFETs according to duty factor (see the equations
below). The conduction losses are the only component of
power dissipation for the lower MOSFETs. Only the upper
MOSFET has switching losses, since the lower device turns
on 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 proportional to the switching frequency
(FS) and are dissipated by the HIP6019B, thus not
contributing to the MOSFETs’ temperature rise. However,
large gate charge increases the switching interval, 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 previous equations even
if the type device is used for both. This is because the gate
drive applied to the upper MOSFET is different than the
lower MOSFET. Figure 14 shows the gate drive where the
upper 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 .
+5V OR LESS
+12V
VCC
HIP6019B
UGATE
Q1
PHASE
NOTE:
VGS ≈ VCC -5V
-
LGATE
Q2
CR1
+
PGND
NOTE:
VGS ≈ VCC
GND
PWM1 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
13
FIGURE 14. OUTPUT GATE DRIVERS
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
FN4587.1
April 13, 2005
HIP6019B
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 might drop
one or two percent as a result. The diode's rated reverse
breakdown voltage must be greater than twice the maximum
input voltage.
PWM2 MOSFET and Schottky Selection
The power dissipation in PWM2 converter power devices is
similar to PWM1 except that the power losses of the lower
device are representative of a Schottky diode instead of a
MOSFET. The transistor power losses follow the PWM1
upper MOSFET equation, so the selection process should
be somewhat similar. The equation below describes the
conduction power losses incurred by the Schottky diode.
I O × V f × ( V IN – V OUT )
P SCH = -----------------------------------------------------------V IN
As it can be observed, conduction losses in the Schottky
diode are proportional with the forward voltage drop (Vf).
Linear Controller MOSFET Selection
The main criteria for selection of MOSFET for the linear
regulator 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 maximum rating while operating at
the highest expected ambient temperature.
HIP6019B DC-DC Converter Application
Circuit
Figure 15 shows an application circuit of a power supply for
a microprocessor computer system. The power supply
provides the microprocessor core voltage (VOUT1), the I/O
voltage (VOUT2), the GTL bus voltage (VOUT3) and clock
generator voltage (VOUT4) from +5VDC and +12VDC. For
detailed information on the circuit, including a Bill-ofMaterials and circuit board description, see Application Note
AN9800. Also see Intersil’s web page
(http://www.intersil.com).
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software 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 www.intersil.com
14
FN4587.1
April 13, 2005
HIP6019B
+12VIN
L1
F1
+5VIN
1µH
30A
C1-4 +
4x1000µF
GND
C14-15
2x1µF
C16
1µF
C18
C17
VCC
1000pF
R1
28
1.21K OCSET2
Q3
HUF76137S3S
VOUT2
(3.3V)
UGATE2
L2
PHASE2
1000pF
R2
23
1.21K
OCSET1
9
8
1
27
2
26
POWERGOOD
PGOOD
Q1
HUF76139S3S
UGATE1
PHASE1
L3
5.2µH
+
2.9µH
C19-23
5x1000µF
R3
4.99K
R5
FB2
3.32K
0.68µF
R21
C38
COMP2
LGATE1
25
CR2
MBR2535CTL
VSEN2
C37
15
22
10
21
HIP6019B
R4
4.99K
VSEN1
R7
2.21K
Q4
HUF75307D3S
VOUT3
(GTL = 1.5V)
COMP1
FB3
7
18
6
5
19
1.87K
3
VOUT4
10K
+
4
R12
10K
R13
C47
270µF
C42
R10
0.01µF
150K
R9
0.1µF
R11
VOUT4
(2.5V)
C41
10pF
GATE3
C43-46
4x1000µF
0.68µF
11
C39
220K
5.11K
C40
R8
FB1
20
R6
C24-36 +
7x1000µF
Q2
HUF76139S3S
PGND
24
10pF
+
VOUT1
(1.3 TO 3.5V)
FB4
R14
10K
16
12
VID0
VID1
VID2
VID3
VID4
VID1
VID2
VID3
VID4
SS
14
13
732K
VID0
17
C48
0.039µF
GND
FAULT/RT
FIGURE 15. APPLICATION CIRCUIT
15
FN4587.1
April 13, 2005