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DATASHEET
ISL8510
Dual Output Controller with 1A Standard Buck PWM and LDO
FN6516 Rev 2.00 December 15, 2008
The ISL8510 is a high-performance, dual output controller that provides a single, high frequency power solution for a variety of point of load applications. The ISL8510 integrates a 1A standard buck PWM controller and switching MOSFET with one 500mA LDO.
The PWM controller in the ISL8510 drives an internal switching N-Channel power MOSFET and requires an external Schottky diode to generate an output voltage from 0.6V to 20V. The integrated power switch is optimized for excellent thermal performance up to 1A of output current. The standard buck input voltage range supports a fixed 5V or variable 5.5V to 25V range. The PWM regulator switches at a fixed frequency of 500kHz and utilizes simple voltage mode control with input voltage feed forward to provide flexibility in component selection and minimize solution size. Protection features include overcurrent, undervoltage, and thermal overload protection integrated into the IC. The ISL8510 power-good signal output indicates loss of regulation on the PWM output.
The ISL8510 features one adjustable LDO regulator using internal PMOS transistors as pass devices. The enable pin (EN_LDO) controls the LDO output. A single power-good signal output indicates loss of regulation on the LDO output. Independent overcurrent and thermal fault shutdown monitors are integrated into the “LDO Regulator Capacitor Selection” on page 16.
The ISL8510 is available in a small 4mmx4mm Quad Flat No Lead (QFN) package.
Features
• Standard Buck Controller with Integrated Switching Power MOSFET + 1 LDO
• Integrated Boot Diode
• Input Voltage Range - Fixed 5V ±10% - Variable 5.5V to 25V
• PWM Output Voltage Adjustable from 0.6V to 20V with Continuous Output Current up to 1A
• Voltage Mode Control with Voltage Feed Forward
• Fixed 500kHz Switching Frequency
• Externally Adjustable Soft-Start Time
• Output Undervoltage Protection
• LDO Adjustable Options - LDO, 0.6V to 4.2V . . . . . . . . . . . . . . . . . . . . . . . 500mA
• Individual Enable Inputs
• Two PGOOD Outputs (PWM and LDO)
• Overcurrent Protection
• Thermal Overload Protection
• Internal 5V LDO regulator
• Pb-Free (RoHS Compliant)
Applications
• General Purpose
• WLAN Cards-PCMCIA, Cardbus32, MiniPCI CardsCompact Flash Cards
• Hand-Held Instruments
FN6516 Rev 2.00 December 15, 2008
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ISL8510
Pinout
ISL8510 (24 LD QFN) TOP VIEW
CC PG_PWM FB_PWM COMP SS EN
24 23 22 21 20 19
FB_LDO 1
18 VIN
VOUT 2
17 VIN
VIN_LDO 3 GND 4
25 GND
16 PHASE 15 PHASE
GND 5
14 BOOT
NC 6
13 PVCC
7 8 9 10 11 12
Ordering Information
PART NUMBER
(Note)
PART
TEMP.
MARKING RANGE (°C)
PACKAGE (Pb-free)
PKG. DWG. #
ISL8510IRZ* 85 10IRZ -40 to +85 24 Ld 4x4 QFN L24.4x4D
*Add “-T” suffix for tape and reel. Please refer to TB347 for details on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is 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.
NC PG_LDO EN_LDO
GND GND VCC
FN6516 Rev 2.00 December 15, 2008
Page 2 of 21
ISL8510
Typical Application Schematics
R5 5.11k
LDO
R6 5.11k
1.2V
C6 22µF
VOUT1
C7 10µF
C4 0.1µF
FB_LDO VOUT
VIN_LDO
CC1 PG_PWM EN_PWM SS
PWM PGOOD PWM ENABLE
R2 2.21k C5 0.033µF
R3 C1 301 100pF
C2 10nF R4 20k
C3 10pF
R1 10k
VOUT
FB_PWM COMP
ISL8510
VIN C9
10µF
PHASE C10
BOOT 0.1µF
5V
UNREGULATED ~2.5V
L1 10µH
VOUT1
C11 +3.3V 100µF
PVCC
VCC
GND
PG_LDO EN_LDO
C14 1µF
VIN
LDO PGOOD LDO ENABLE
FIGURE 1. VIN RANGE FROM 4.5V TO 5.5V
FN6516 Rev 2.00 December 15, 2008
Page 3 of 21
ISL8510
Typical Application Schematics (Continued)
PWM PGOOD PWM ENABLE
C4 0.1µF
R2 2.21k
C5 0.033µF
R3 C1 301 100pF
C2 10nF
R4 20k
C3 10pF
R1 10k
VOUT
FB_PWM COMP
CC1 PG_PWM EN SS
R5 5.11k
LDO 1.2V
R6 5.11k
C6 22µF
VOUT
C7 10µF
FB_LDO VOUT
VIN_LDO
ISL8510
VIN
C9 10µF
5V
UNREGULATED ~2.5V
PHASE C10
BOOT 0.1µF
L1 10µH
D B340LB
VOUT +3.3V C11 100µF
PVCC
VCC
GND
EN_LDO1
PG_LDO
C14 1µF
LDO1 ENABLE
LDO PGOOD
FIGURE 2. VIN RANGE FROM 5.5V TO 25V
FN6516 Rev 2.00 December 15, 2008
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ISL8510
Functional Block Diagram
FB COMP PVCC BOOT
VCC SOFT-START CONTROL
30µA
VOLTAGE MONITOR
SS
EN_PWM EN_LDO
FAULT MONITOR
VCC
VIN
PG_PWM
LDO
POWER-ON RESET
MONITOR
-+ -+
PWM EA
OC MONITOR
0.6V REFERENCE
RAMP GENERATOR
VIN
GATE DRIVE
THERMAL MONITOR
+150°C OC MONITOR
OSCILLATOR
POR
PVCC VIN_LDO
Gm
REF POR FAULT
LDO CONTROL
LOGIC
WINDOW COMP.
+LDO
PG_LDO
VIN (x2)
PHASE (x2)
CC1 VIN_LDO VOUT FB_LDO
GND
FN6516 Rev 2.00 December 15, 2008
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