HIP6005B
TM
Data Sheet
February 1999
FN4568.2
Buck Pulse-Width Modulator (PWM)
Controller and Output Voltage Monitor
The HIP6005B provides complete control and protection for
a DC-DC converter optimized for high-performance
microprocessor applications. It is designed to drive an
N-Channel MOSFET in a standard buck topology. The
HIP6005B integrates all of the control, output adjustment,
monitoring and protection functions into a single package.
The output voltage of the converter is easily adjusted and
precisely regulated. The HIP6005B includes a fully
TTL-compatible 5-input digital-to-analog converter (DAC)
that adjusts the output voltage from 1.3V
DC
to 2.05V
DC
in
0.05V increments and from 2.1V
DC
to 3.5V
DC
in 0.1V steps.
The precision reference and voltage-mode regulator hold the
selected output voltage to within
±1%
over temperature and
line voltage variations.
The HIP6005B provides simple, single feedback loop, voltage-
mode control with fast transient response. It includes a 200kHz
free-running triangle-wave oscillator that is adjustable from
below 50kHz to over 1MHz. The error amplifier features a
15MHz gain-bandwidth product and 6V/µs slew rate which
enables high converter bandwidth for fast transient
performance. The resulting PWM duty ratio ranges from 0% to
100%.
The HIP6005B monitors the output voltage with a window
comparator that tracks the DAC output and issues a Power
Good signal when the output is within
±10%.
The HIP6005B
protects against over-current and over-voltage conditions by
inhibiting PWM operation. Additional built-in over-voltage
protection triggers an external SCR to crowbar the input
supply. The HIP6005B monitors the current by using the
r
DS(ON)
of the upper MOSFET which eliminates the need for
a current sensing resistor.
Features
• Drives N-Channel MOSFET
• Operates from +5V or +12V Input
• Simple Single-Loop Control Design
- Voltage-Mode PWM Control
• Fast Transient Response
- High-Bandwidth Error Amplifier
- Full 0% to 100% Duty Ratio
• Excellent Output Voltage Regulation
-
±1%
Over Line Voltage and Temperature
• TTL-Compatible 5-Bit Digital-to-Analog Output Voltage
Selection
- Wide Range . . . . . . . . . . . . . . . . . . . 1.3V
DC
to 3.5V
DC
- 0.1V Binary Steps . . . . . . . . . . . . . . 2.1V
DC
to 3.5V
DC
- 0.05V Binary Steps . . . . . . . . . . . . 1.3V
DC
to 2.05V
DC
• Power-Good Output Voltage Monitor
• Over-Voltage and Over-Current Fault Monitors
- Does Not Require Extra Current Sensing Element,
Uses MOSFET’s r
DS(ON)
• Small Converter Size
- Constant Frequency Operation
- 200kHz Free-Running Oscillator Programmable from
50kHz to over 1MHz
Applications
• Power Supply for Pentium®, Pentium Pro, Pentium II,
PowerPC™, K6™, 6X86™ and Alpha™ Microprocessors
• High-Power 5V to 3.xV DC-DC Regulators
• Low-Voltage Distributed Power Supplies
Pinout
HIP6005B
(SOIC, TSSOP)
TOP VIEW
VSEN
OCSET
1
2
3
4
5
6
7
8
9
20 RT
19 OVP
18 VCC
17 NC
16 NC
15 BOOT
14 UGATE
13 PHASE
12 PGOOD
11 GND
Ordering Information
PART NUMBER
HIP6005BCB
HIP6005BCV
TEMP.
RANGE (
o
C)
0 to 70
0 to 70
PACKAGE
20 Ld SOIC
20 Ld TSSOP
PKG.
NO.
M20.3
M20.173
SS
VID0
VID1
VID2
VID3
VID4
COMP
NOTE: When ordering, use the entire part number. Add the suffix T
to obtain the TSSOP variant in tape and reel, e.g., HIP6005BCV-T.
FB 10
6X86™ is a trademark of Cyrix Corporation.
Alpha Micro™ is a trademark of Digital Computer Equipment Corporation
K6™ is a trademark of Advanced Micro Devices.
Pentium® is a registered trademark of Intel Corporation.
PowerPC™ is a registered trademark of IBM.
110
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
|
Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002. All Rights Reserved
HIP6005B
Typical Application
+12V
VCC
PGOOD
SS
OVP
RT
OSC
VID0
VID1
VID2
VID3
VID4
FB
UGATE
D/A
HIP6005B
PHASE
+V
OUT
+
+
MONITOR AND
PROTECTION
BOOT
OCSET
V
IN
= +5V OR +12V
-
-
COMP
VSEN
GND
Block Diagram
VCC
VSEN
110%
+
POWER-ON
RESET (POR)
-
90%
+
PGOOD
-
115%
+
OVER-
VOLTAGE
10µA
OVP
SOFT-
START
OVER-
CURRENT
4V
SS
BOOT
UGATE
PHASE
VID0
VID1
VID2
VID3
VID4
FB
COMP
GND
RT
OSCILLATOR
D/A
CONVERTER
(DAC)
DACOUT
+
PWM
COMPARATOR
GATE
CONTROL
LOGIC
-
+
OCSET
200µA
-
REFERENCE
-
+
INHIBIT
PWM
-
ERROR
AMP
HIP6005B
Absolute Maximum Ratings
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+15V
Boot Voltage, V
BOOT
- V
PHASE
. . . . . . . . . . . . . . . . . . . . . . . .+15V
Input, Output or I/O Voltage . . . . . . . . . . . . GND -0.3V to V
CC
+0.3V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 2
Thermal Information
Thermal Resistance (Typical, Note 1)
θ
JA
(
o
C/W)
Operating Conditions
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . +12V
±10%
Ambient Temperature Range. . . . . . . . . . . . . . . . . . . . . 0
o
C to 70
o
C
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
110
2
of Copper) . . . . . . . . . . . .
86
SOIC Package (with 3in
TSSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . .
140
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . 150
o
C
Maximum Storage Temperature Range . . . . . . . . . -65
o
C to 150
o
C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300
o
C
(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.
θ
JA
is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
PARAMETER
V
CC
SUPPLY CURRENT
Nominal Supply
POWER-ON RESET
Rising V
CC
Threshold
Falling V
CC
Threshold
Rising V
OCSET
Threshold
OSCILLATOR
Free Running Frequency
Total Variation
Ramp Amplitude
REFERENCE AND DAC
Recommended Operating Conditions, Unless Otherwise Noted
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
I
CC
UGATE Open
-
5
-
mA
V
OCSET
= 4.5V
V
OCSET
= 4.5V
-
8.2
-
-
-
1.26
10.4
-
-
V
V
V
RT = Open
6kΩ < R
T
to GND < 200kΩ
∆V
OSC
R
T
= Open
185
-15
-
200
-
1.9
215
+15
-
kHz
%
V
P-P
DAC (VID0-VID4) Input Low Voltage
DAC (VID0-VID4) Input High Voltage
DACOUT Voltage Accuracy
ERROR AMPLIFIER
DC Gain
Gain-Bandwidth Product
Slew Rate
GATE DRIVER
Upper Gate Source
Upper Gate Sink
PROTECTION
Over-Voltage Trip (V
SEN
/DACOUT)
OCSET Current Source
OVP Sourcing Current
Soft Start Current
POWER GOOD
Upper Threshold (V
SEN
/DACOUT)
Lower Threshold (V
SEN
/DACOUT)
Hysteresis (V
SEN
/DACOUT)
PGOOD Voltage Low
V
PGOOD
V
SEN
Rising
V
SEN
Falling
Upper and Lower Threshold
I
PGOOD
= -5mA
I
OCSET
I
OVP
I
SS
V
OCSET
= 4.5V
V
SEN
= 5.5V; V
OVP
= 0V
I
UGATE
R
UGATE
V
BOOT
- V
PHASE
= 12V, V
UGATE
= 6V
GBW
SR
COMP = 10pF
-
2.0
-1.0
-
-
-
0.8
-
+1.0
V
V
%
-
-
-
88
15
6
-
-
-
dB
MHz
V/µs
350
-
500
5.5
-
10
mA
W
-
170
60
-
115
200
-
10
120
230
-
-
%
µA
mA
µA
106
89
-
-
-
-
2
0.5
111
94
-
-
%
%
%
V
HIP6005B
Typical Performance Curves
40
35
RESISTANCE (kΩ)
1000
R
T
PULLUP
TO +12V
I
CC
(mA)
30
25
20
15
10
R
T
PULLDOWN TO V
SS
5
0
100
10
C
UGATE
= 10pF
C
UGATE
= 1000pF
C
UGATE
= 3300pF
100
10
100
SWITCHING FREQUENCY (kHz)
1000
200
300
400
500
600
700
800
900
1000
SWITCHING FREQUENCY (kHz)
FIGURE 1. R
T
RESISTANCE vs FREQUENCY
FIGURE 2. BIAS SUPPLY CURRENT vs FREQUENCY
Functional Pin Description
VID0-4 (Pins 4-8)
VSEN
OCSET
SS
VID0
VID1
VID2
VID3
VID4
COMP
1
2
3
4
5
6
7
8
9
20 RT
19 OVP
18 VCC
17 NC
16 NC
15 BOOT
14 UGATE
13 PHASE
12 PGOOD
11 GND
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 converter output
voltage. It also sets the PGOOD and OVP thresholds. Table
1 specifies DACOUT for the 32 combinations of DAC inputs.
COMP (Pin 9) and FB (Pin 10)
COMP and FB are the available external pins of the error
amplifier. The FB pin is the inverting input of the error
amplifier and the COMP pin is the error amplifier output.
These pins are used to compensate the voltage-control
feedback loop of the converter.
FB 10
VSEN (Pin 1)
This pin is connected to the converters output voltage. The
PGOOD and OVP comparator circuits use this signal to
report output voltage status and for overvoltage protection.
GND (Pin 11)
Signal ground for the IC. All voltage levels are measured
with respect to this pin.
PGOOD (Pin 12)
PGOOD is an open collector output used to indicate the
status of the converter output voltage. This pin is pulled low
when the converter output is not within
±10%
of the
DACOUT reference voltage. Exception to this behavior is the
‘11111’ VID pin combination which disables the converter; in
this case PGOOD asserts a high level.
OCSET (Pin 2)
Connect a resistor (R
OCSET
) from this pin to the drain of the
upper MOSFET. R
OCSET
, an internal 200µA current source
(I
OCS
), and the upper MOSFET on-resistance (r
DS(ON)
) set
the converter over-current (OC) trip point according to the
following equation:
I
OCSET
x R
OCSET
I
PEAK
= ----------------------------------------------------
-
r
DS
(
ON
)
PHASE (Pin 13)
Connect the PHASE pin to the upper MOSFET source. This
pin is used to monitor the voltage drop across the MOSFET
for over-current protection. This pin also provides the return
path for the upper gate drive.
An over-current trip cycles the soft-start function.
SS (Pin 3)
Connect a capacitor from this pin to ground. This capacitor,
along with an internal 10µA current source, sets the
soft-start interval of the converter.
UGATE (Pin 14)
Connect UGATE to the upper MOSFET gate. This pin
provides the gate drive for the upper MOSFET.
HIP6005B
BOOT (Pin 15)
This pin provides bias voltage to the upper MOSFET driver.
A bootstrap circuit may be used to create a BOOT voltage
suitable to drive a standard N-Channel MOSFET.
the SS voltage reaches the valley of the oscillator’s triangle
wave. The oscillator’s triangular waveform is compared to the
ramping error amplifier voltage. This generates PHASE
pulses of increasing width that charge the output capacitor(s).
This interval of increasing pulse width continues to t
2
. With
sufficient output voltage, the clamp on the reference input
controls the output voltage. This is the interval between t
2
and
t
3
in Figure 3. At t
3
the SS voltage exceeds the DACOUT
voltage and the output voltage is in regulation. This method
provides a rapid and controlled output voltage rise. The
PGOOD signal toggles ‘high’ when the output voltage (V
SEN
pin) is within
±5%
of DACOUT. The 2% hysteresis built into
the power good comparators prevents PGOOD oscillation due
to nominal output voltage ripple.
NC (Pin 16)
No connection.
NC (Pin 17)
No connection.
VCC (Pin 18)
Provide a 12V bias supply for the chip to this pin.
OVP (Pin 19)
The OVP pin can be used to drive an external SCR in the
event of an overvoltage condition. Output rising 15% more
than the DAC-set voltage triggers a high output on this pin
and disables PWM gate drive circuitry.
RT (Pin 20)
This pin provides oscillator switching frequency adjustment.
By placing a resistor (R
T
) from this pin to GND, the nominal
200kHz switching frequency is increased according to the
following equation:
5 x 10
-
Fs
≈
200kHz
+ --------------------
R
T
(
kΩ
)
6
PGOOD
(2V/DIV.)
0V
SOFT-START
(1V/DIV.)
OUTPUT
VOLTAGE
(1V/DIV.)
0V
0V
t
1
t
2
TIME (5ms/DIV.)
t
3
(R
T
to GND)
Conversely, connecting a pull-up resistor (R
T
) from this pin
to V
CC
reduces the switching frequency according to the
following equation:
4 x 10
-
Fs
≈
200kHz
– --------------------
R
T
(
k
Ω)
7
FIGURE 3. SOFT START INTERVAL
(R
T
to 12V)
Over-Current Protection
The over-current function protects the converter from a
shorted output by using the upper MOSFET’s on-resistance,
r
DS(ON)
to monitor the current. This method enhances the
converter’s efficiency and reduces cost by eliminating a
current sensing resistor.
SOFT-START
OUTPUT INDUCTOR
Functional Description
Initialization
The HIP6005B automatically initializes upon receipt of 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 at the V
CC
pin and the input voltage (V
IN
) on the OCSET pin. The level on
OCSET is equal to V
IN
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. For operation with a single +12V power source, V
IN
and V
CC
are equivalent and the +12V power source must
exceed the rising V
CC
threshold before POR initiates operation.
4V
2V
0V
15A
10A
5A
0A
Soft Start
The POR function initiates the soft start sequence. An internal
10µA current source charges an external capacitor (C
SS
) on
the SS pin to 4V. Soft start clamps the error amplifier output
(COMP pin) and reference input (+ terminal of error amp) to
the SS pin voltage. Figure 3 shows the soft start interval with
C
SS
= 0.1µF. Initially the clamp on the error amplifier (COMP
pin) controls the converter’s output voltage. At t
1
in Figure 3,
TIME (20ms/DIV.)
FIGURE 4. OVER-CURRENT OPERATION
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