HIP6007
Data Sheet
September 1997
File Number
4307.1
Buck Pulse-Width Modulator (PWM)
Controller
The HIP6007 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
HIP6007 integrates all of the control, output adjustment,
monitoring and protection functions into a single package.
The output voltage of the converter can be precisely
regulated to as low as 1.27V, with a maximum tolerance of
±1%
over temperature and line voltage variations.
The HIP6007 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 HIP6007 protects against over-current conditions by
inhibiting PWM operation. The HIP6007 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
- 1.27V Internal Reference
-
±1%
Over Line Voltage and Temperature
• Over-Current Fault Monitor
- 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
• 14 Pin, SOIC Package
Applications
• Power Supply for Pentium®, Pentium Pro, PowerPC™ and
Alpha™ Microprocessors
• High-Power 5V to 3.xV DC-DC Regulators
• Low-Voltage Distributed Power Supplies
Pinout
HIP6007
(SOIC)
TOP VIEW
RT
OCSET
SS
COMP
FB
EN
1
2
3
4
5
6
14 VCC
13 NC
12 NC
11 NC
10 BOOT
9
8
UGATE
PHASE
Ordering Information
PART NUMBER
HIP6007CB
TEMP. RANGE
(
o
C)
0 to 70
PACKAGE
14 Ld SOIC
PKG.
NO.
M14.15
GND 7
PowerPC™ is a trademark of IBM.
Alpha™ is a trademark of Digital Equipment Corporation.
Pentium® is a registered trademark of Intel Corporation.
2-131
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
HIP6007
Typical Application
+12V
VCC
SS
OCSET
MONITOR AND
PROTECTION
EN
BOOT
RT
OSC
+5V OR +12V
UGATE
PHASE
+V
O
HIP6007
REF
-
+
FB
+
-
COMP
Block Diagram
VCC
POWER-ON
RESET (POR)
10µA
+
OCSET
EN
-
OVER-
CURRENT
4V
SOFT-
START
SS
BOOT
UGATE
PHASE
200µA
1.27 VREF
REFERENCE
+
PWM
COMPARATOR
-
+
INHIBIT
PWM
-
GATE
CONTROL
LOGIC
FB
COMP
ERROR
AMP
GND
RT
OSCILLATOR
2-132
HIP6007
Absolute Maximum Ratings
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +15.0V
Boot Voltage, V
BOOT
- V
PHASE
. . . . . . . . . . . . . . . . . . . . . . . +15.0V
Input, Output or I/O Voltage . . . . . . . . . . . GND -0.3V to VCC +0.3V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 2
Thermal Information
Thermal Resistance (Typical, Note 1)
θ
JA
(
o
C/W)
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
150
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)
Operating Conditions
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . +12V
±10%
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . . 0
o
C to 70
o
C
Junction Temperature Range . . . . . . . . . . . . . . . . . . . . 0
o
C to 125
o
C
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
VCC SUPPLY CURRENT
Nominal Supply
Shutdown Supply
POWER-ON RESET
Rising VCC Threshold
Falling VCC Threshold
Enable - Input threshold Voltage
Rising V
OCSET
Threshold
OSCILLATOR
Free Running Frequency
Total Variation
Ramp Amplitude
REFERENCE
Reference Voltage
ERROR AMPLIFIER
DC Gain
Gain-Bandwidth Product
Slew Rate
GATE DRIVERS
Upper Gate Source
Upper Gate Sink
PROTECTION
OCSET Current Source
Soft Start Current
Recommended Operating Conditions, Unless Otherwise Noted
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
I
CC
EN = VCC; UGATE and LGATE Open
EN = 0V
-
-
5
50
-
100
mA
µA
V
OCSET
= 4.5VDC
V
OCSET
= 4.5VDC
V
OCSET
= 4.5VDC
-
8.2
0.8
-
-
-
-
1.27
10.4
-
2.0
-
V
V
V
V
RT = OPEN, V
CC
= 12
6kΩ < RT to GND < 200kΩ
∆V
OSC
RT = OPEN
185
-15
-
200
-
1.9
215
+15
-
kHz
%
V
P-P
1.258
1.270
1.282
V
-
GBW
SR
COMP = 10pF
-
-
88
15
6
-
-
-
dB
MHz
V/µs
I
UGATE
R
UGATE
V
BOOT
- V
PHASE
= 12V, V
UGATE
= 6V
I
LGATE
= 0.3A
350
-
500
5.5
-
10
mA
Ω
I
OCSET
I
SS
V
OCSET
= 4.5VDC
170
-
200
10
230
-
µA
µA
2-133
HIP6007
Typical Performance Curves
40
35
1000
RESISTANCE (kΩ)
R
T
PULLUP
TO +12V
C
GATE
= 3300pF
30
25
100
R
T
PULLDOWN
TO V
SS
I
CC
(mA)
20
15
10
5
0
100
C
GATE
= 10pF
C
GATE
= 1000pF
10
10
100
SWITCHING FREQUENCY (kHz)
1000
200
300 400 500 600 700 800
SWITCHING FREQUENCY (kHz)
900
1000
FIGURE 1. R
T
RESISTANCE vs FREQUENCY
FIGURE 2. BIAS SUPPLY CURRENT vs FREQUENCY
Functional Pin Description
RT
OCSET
SS
COMP
FB
EN
1
2
3
4
5
6
14 VCC
13 NC
12 NC
11 NC
10 BOOT
9
8
UGATE
PHASE
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.
COMP (Pin 4) and FB (Pin 5)
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.
GND 7
RT (Pin 1)
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
•
10
Fs
≈
200kHz
+ --------------------
-
R
T
(
kΩ
)
6
EN (Pin 6)
This pin is the open-collector enable pin. Pull this pin below
1V to disable the converter. In shutdown, the soft start pin is
discharged and the UGATE and LGATE pins are held low.
GND (Pin 7)
(R
T
to GND)
Signal ground for the IC. All voltage levels are measured with
respect to this pin.
Conversely, connecting a pull-up resistor (R
T
) from this pin
to VCC reduces the switching frequency according to the
following equation.:
4
•
10
Fs
≈
200kHz
– --------------------
-
R
T
(
kΩ
)
7
PHASE (Pin 8)
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.
(R
T
to 12V)
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
OCS
•
R
OCSET
I
PEAK
= -------------------------------------------
-
r
DS
(
ON
)
UGATE (Pin 9)
Connect UGATE to the upper MOSFET gate. This pin
provides the gate drive for the upper MOSFET.
BOOT (Pin 10)
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.
VCC (Pin 14)
Provide a 12V bias supply for the chip to this pin.
An over-current trip cycles the soft-start function.
2-134
HIP6007
Functional Description
Initialization
The HIP6007 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 and the enable (EN) pin. The POR
monitors the bias voltage at the VCC 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). With the EN pin held to VCC, 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.
The Power-On Reset (POR) function inhibits operation with
the chip disabled (EN pin low). With both input supplies
above their POR thresholds, transitioning the EN pin high
initiates a soft start interval.
SOFT-START
(1V/DIV)
0V
0V
t1
t2
OUTPUT
VOLTAGE
(1V/DIV)
t3
TIME (5ms/DIV)
FIGURE 3. SOFT-START INTERVAL
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.
The over-current function cycles the soft-start function in a
hiccup mode to provide fault protection. A resistor (R
OCSET
)
programs the over-current trip level. An internal 200µA
(typical) current sink develops a voltage across R
OCSET
that
is reference to V
IN
. When the voltage across the upper
MOSFET (also referenced to V
IN
) exceeds the voltage
across R
OCSET
, the over-current function initiates a soft-
start sequence. The soft-start function discharges C
SS
with
a 10µA current sink and inhibits PWM operation. The soft-
start function recharges C
SS
, and PWM operation resumes
with the error amplifier clamped to the SS voltage. Should an
overload occur while recharging C
SS
, the soft start function
inhibits PWM operation while fully charging C
SS
to 4V to
complete its cycle. Figure 4 shows this operation with an
overload condition. Note that the inductor current increases
to over 15A during the C
SS
charging interval and causes an
over-current trip. The converter dissipates very little power
with this method. The measured input power for the
conditions of Figure 4 is 2.5W.
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 t1 in Figure 3,
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 t2. With
sufficient output voltage, the clamp on the reference input
controls the output voltage. This is the interval between t2 and
t3 in Figure 3. At t3 the SS voltage exceeds the reference
voltage and the output voltage is in regulation. This method
provides a rapid and controlled output voltage rise.
2-135
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