E ND
OMM 35
R EC
65
RSIL CT - ISL
TE
U
, IN
Data
S
Sheet
ROD
IGN ED P
D ES
C
N EW EN H A N
R
FO
P- I N
D RO
®
S
ISL6522
March 10, 2006
FN9030.8
Buck and Synchronous Rectifier
Pulse-Width Modulator (PWM) Controller
The ISL6522 provides complete control and protection for a
DC-DC converter optimized for high-performance micro-
processor applications. It is designed to drive two N-Channel
MOSFETs in a synchronous rectified buck topology. The
ISL6522 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 0.8V, with a maximum tolerance of
±1%
over temperature and line voltage variations.
The ISL6522 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 0–100%.
The ISL6522 protects against overcurrent conditions by
inhibiting PWM operation. The ISL6522 monitors the current
by using the r
DS(ON)
of the upper MOSFET which eliminates
the need for a current sensing resistor.
Features
• Drives two N-Channel MOSFETs
• Operates from +5V or +12V input
• Simple single-loop control design
- Voltage-mode PWM control
• Fast transient response
- High-bandwidth error amplifier
- Full 0–100% duty ratio
• Excellent output voltage regulation
- 0.8V internal reference
-
±1%
over line voltage and temperature
• Overcurrent fault monitor
- Does not require extra current sensing element
- Uses MOSFETs r
DS(ON)
• Converter can source and sink current
• Small converter size
- Constant frequency operation
- 200kHz free-running oscillator programmable from
50kHz to over 1MHz
• 14-lead SOIC and TSSOP package and 16-lead 5x5mm
QFN Package
• QFN Package
- Compliant to JEDEC PUB95 MO-220 QFN-Quad Flat
No Leads-Product Outline.
- Near Chip-Scale Package Footprint; Improves PCB
Efficiency and Thinner in Profile
• Pb-free plus anneal available (RoHS compliant)
Pinouts
RT
OCSET
SS
COMP
FB
EN
GND
1
2
3
4
5
6
7
SOIC, TSSOP
TOP VIEW
14 VCC
13 PVCC
12 LGATE
11 PGND
10 BOOT
9
8
UGATE
PHASE
Applications
• Power supply for Pentium
®
, Pentium Pro, PowerPC
®
and
AlphaPC™ microprocessors
• High-power 5V to 3.xV DC-DC regulators
• Low-voltage distributed power supplies
QFN
TOP VIEW
OCSET
VCC
13
12 PVCC
11 LGATE
GND
FB 3
EN 4
5
NC
6
GND
7
PHASE
8
UGATE
10 PGND
9
BOOT
NC
16
SS 1
COMP 2
15
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
|
Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2001, 2002, 2004-2006. All Rights Reserved
PowerPC
®
is a trademark of IBM. AlphaPC™ is a trademark of Digital Equipment Corporation. Pentium
®
is a registered trademark of Intel Corporation.
1
RT
14
ISL6522
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 V
CC
+0.3V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 2
Thermal Information
Thermal Resistance (Typical, Note 1)
θ
JA
(°C/W)
θ
JC
(°C/W)
SOIC Package (Note 1) . . . . . . . . . . . .
67
n/a
TSSOP Package (Note 1) . . . . . . . . . .
95
n/a
QFN Package (Notes 2, 3). . . . . . . . . .
36
5
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . 150°C
Maximum Storage Temperature Range . . . . . . . . . . . -65°C to 150°C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300°C
(SOIC - Lead Tips Only)
Recommended Operating Conditions
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . +12V
±10%
Ambient Temperature Range, ISL6522C . . . . . . . . . . . . 0°C to 70°C
Ambient Temperature Range, ISL6522I. . . . . . . . . . . .-40°C to 85°C
Junction Temperature Range, ISL6522C. . . . . . . . . . . 0°C to 125°C
Junction Temperature Range, ISL6522I . . . . . . . . . .-40°C to 125°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.
NOTES:
1.
θ
JA
is measured with the component mounted on a highs effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
2.
θ
JA
is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. SeeTech
Brief TB379.
3. For
θ
JC
, the "case temp" location is the center of the exposed metal pad on the package underside.
Electrical Specifications
PARAMETER
V
CC
SUPPLY CURRENT
Nominal Supply
Shutdown Supply
POWER-ON RESET
Rising V
CC
Threshold
Falling V
CC
Threshold
Enable-Input Threshold Voltage
Recommended Operating Conditions, Unless Otherwise Noted
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
I
CC
EN = V
CC
; UGATE and LGATE Open
EN = 0V
-
-
5
50
-
100
mA
µA
V
OCSET
= 4.5VDC
V
OCSET
= 4.5VDC
ISL6522C, V
OCSET
= 4.5VDC
ISL6522I, V
OCSET
= 4.5VDC
-
8.1
0.8
0.8
-
-
-
-
-
1.27
10.4
-
2.0
2.1
-
V
V
V
V
V
Rising V
OCSET
Threshold
OSCILLATOR
Free Running Frequency
ISL6522C, R
T
= OPEN, V
CC
= 12
ISL6522I, R
T
= OPEN, V
CC
= 12
Total Variation
Ramp Amplitude
REFERENCE
Reference Voltage Tolerance
V
REF
Commercial
Industrial
Reference Voltage
ERROR AMPLIFIER
DC Gain
Gain-Bandwidth Product
Slew Rate
GATE DRIVERS
Upper Gate Source
I
UGATE
V
BOOT
- V
PHASE
= 12V, V
UGATE
= 6V
GBW
SR
COMP = 10pF
∆V
OSC
6kΩ < R
T
to GND < 200kΩ
R
T
= OPEN
175
160
-20
-
200
200
-
1.9
230
230
+20
-
kHz
%
V
P-P
-1
-2
-
-
-
0.800
1
+1
-
%
%
V
-
-
-
88
15
6
-
-
-
dB
MHz
V/µs
350
500
-
mA
4
FN9030.8
March 10, 2006
ISL6522
Electrical Specifications
PARAMETER
Upper Gate Sink
Recommended Operating Conditions, Unless Otherwise Noted
(Continued)
SYMBOL
R
UGATE
TEST CONDITIONS
ISL6522C, I
LGATE
= 0.3A
ISL6522I, I
LGATE
= 0.3A
Lower Gate Source
Lower Gate Sink
I
LGATE
R
LGATE
V
CC
= 12V, V
LGATE
= 6V
ISL6522C, I
LGATE
= 0.3A
ISL6522I, I
LGATE
= 0.3A
PROTECTION
OCSET Current Source
Soft-Start Current
I
OCSET
I
SS
V
OCSET
= 4.5VDC
170
-
200
10
230
-
µA
µA
MIN
-
-
300
-
-
TYP
5.5
5.5
450
3.5
3.5
MAX
10
7.2
-
6.5
4.5
UNITS
Ω
Ω
mA
Ω
Ω
Typical Performance Curves
80
70
60
C
GATE
= 3300pF
I
VCC
(mA)
50
40
30
20
10
0
100
C
GATE
= 10pF
C
GATE
= 1000pF
1000
RESISTANCE (kΩ)
R
T
PULLUP
TO +12V
100
R
T
PULLDOWN
TO V
SS
10
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 Descriptions
SOIC
and
TSSOP
RT
OCSET
SS
COMP
FB
EN
1
2
3
4
5
6
14 VCC
13 PVCC
12 LGATE
11 PGND
10 BOOT
9
8
OCSET
UGATE
PHASE
RT
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
6
(R
T
to GND)
GND 7
QFN
SS 1
COMP 2
VCC
Conversely, connecting a pull-up resistor (R
T
) from this pin
to V
CC
reduces the switching frequency according to the
following equation:
4
•
10
Fs
≈
200kHz
– ------------------
R
T
7
NC
16
15
RT
14
13
12 PVCC
11 LGATE
(R
T
to 12V)
GND
FB 3
EN 4
5
NC
6
GND
7
PHASE
8
UGATE
10 PGND
9
BOOT
5
FN9030.8
March 10, 2006