ISL6535CBZ-T Datasheet ISL6535IRZ, ISL6535IBZ-T, ISL6535IRZ-T | P1-P3

DATASHEET

Synchronous Buck Pulse-Width Modulator (PWM)

Controller

ISL6535

The ISL6535 is a high performance synchronous controller for

demanding DC/DC converter applications. It provides

overcurrent fault protection and is designed to safely start-up

into prebiased output loads.

The output voltage of the converter can be precisely regulated

to as low as 0.597V, with a maximum tolerance of ±1% over

the commercial temperature range, and ±1.5% over the

industrial temperature range.

The ISL6535 provides simple, single feedback loop, voltage

mode control with fast transient response. It includes a

triangle wave oscillator that is adjustable from below 50kHz to

over 1.5MHz. Full (0% to 100%) PWM duty cycle support is

provided.

The error amplifier features a 15MHz gain bandwidth product

and 6V/µs slew rate, which enables high converter bandwidth

for fast transient performance.

The ISL6535's overcurrent protection monitors the current by

using the r

DS(ON)

of the upper MOSFET, which eliminates the

need for a current sensing resistor.

Pin Configurations

ISL6535 (14 LD SOIC)

TOP VIEW

ISL6535 (16 LD QFN)

TOP VIEW

Features

• Operates from +12V input

• Excellent output voltage regulation

- 0.597V internal reference

- ±1% over the commercial temperature range

- ±1.5% over the industrial temperature range

• Simple single-loop control design

- Voltage-mode PWM control

• Fast transient response

- High-bandwidth error amplifier

- Full 0% to 100% duty ratio

- Leading and falling edge modulation

•Small converter size

- Constant frequency operation

- Oscillator programmable from 50kHz to over 1.5MHz

• 12V high-speed MOSFET gate drivers

- 2.0A source/3A sink at 12V low-side gate drive

- 1.25A source/2A sink at 12V high-side gate drive

- Drives two N-channel MOSFETs

• Overcurrent fault monitor

- High-side MOSFET’s r

DS(ON)

sensing

- Reduced ~120ns blanking time

• Converter can source and sink current

• Soft-start done and an external reference pin for tracking

applications are available in the QFN package

• Pin compatible with ISL6522

• Supports start-up into prebiased loads

• Pb-free (RoHS compliant)

Applications

• Power Supply for some Pentium™, PowerPC™, as well as

graphic CPUs

• High-power 12V input DC/DC regulators

• Low-voltage distributed power supplies

COMP

GND

PGND

VCC

UGATE

OCSET

PHASE

PVCC

LGATE

BOOT

SSDONE

COMP

REFIN

PGND

PVCC

UGATE

OCSET

PHASE

VCC

GND

LGATE

BOOT

1516 14 13

6578

PAD

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 owned by Intersil Corporation or one of its subsidiaries.

All other trademarks mentioned are the property of their respective owners.

March 3, 2016

FN9255.3

ISL6535

FN9255.3

March 3, 2016

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Pin Descriptions

PIN #

SOIC

PIN #

QFN PIN NAME DESCRIPTION

1 14 RT This pin provides oscillator switching frequency adjustment. By placing a resistor (R

) from

this pin to GND, the switching frequency is set from between 200kHz and 1.5MHz according

Equation 1

Alternately ISL6535’s switching frequency can be lowered from 200kHz to 50kHz by

connecting the RT pin with a resistor to VCC according to Equation 2

2 15 OCSET The current limit is programmed by connecting this pin with a resistor and capacitor to the

drain of the high-side MOSEFT. A 200µA current source develops a voltage across the

resistor, which is then compared with the voltage developed across the high-side MOSFET. A

blanking period of 120ns is provided for noise immunity.

3 1 SS Connect a capacitor from this pin to ground. This capacitor, along with an internal 30µA

current source, sets the soft-start interval of the converter.

4 2 COMP 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.

53FB

6 4 EN This pin is a TTL compatible input. Pull this pin below 0.8V to disable the converter. In

shutdown the soft-start pin is discharged and the UGATE and LGATE pins are held low.

7 6 GND Signal ground for the IC. All voltage levels are measured with respect to this pin.

8 7 PHASE This pin connects to the source of the high-side MOSFET and the drain of the low-side

MOSFET. This pin represents the return path for the high-side gate driver. During normal

switching, this pin is used for high-side current sensing.

9 8 UGATE Connect UGATE to the upper MOSFET gate. This pin provides the gate drive for the upper

MOSFET.

10 9 BOOT This pin provides bias to the upper MOSFET driver. A bootstrap circuit may be used to create

a BOOT voltage suitable to drive a standard N-channel MOSFET.

11 10 PGND This is the power ground connection. Tie the lower MOSFET source and board ground to this

pin.

12 11 LGATE Connect LGATE to the lower MOSFET gate. This pin provides the gate drive for the lower

MOSFET.

13 12 PVCC Provide a 12V ±10% bias supply for the lower gate drive to this pin. This pin should be

bypassed with a capacitor to PGND.

14 13 VCC Provide a 12V bias supply for the chip to this pin. The pin should be bypassed with a capacitor

to GND.

- 5 REFIN Upon enable if REFIN is less than 2.2V, the external reference pin is used as the control

reference instead of the internal 0.597V reference. An internal 6µA pull-up to 5V is provided

for disabling this functionality.

- 16 SSDONE Provides an open-drain signal at the end of soft-start.

- PAD EPAD The exposed pad is at GND potential, but does not conduct current; the GND and PGND pins

must be used for bias current. The pad should be tied to a GND plane with as many thermal

vias as possible, for optimal thermal performance.

k

6500

kHz200 kHz–

-------------------------------------------------------

1.3k–

to GND)

(EQ. 1)

k

55000

200 kHzF

kHz–

-------------------------------------------------------

70k+

to VCC)

(EQ. 2)

ISL6535

FN9255.3

March 3, 2016

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Ordering Information

PART NUMBER

(Notes 4

, 5)

PART

MARKING

TEMP.

RANGE (°C)

PACKAGE

(RoHS Compliant)

PKG.

DWG. #

ISL6535CBZ (Note 1) 6535CBZ 0 to +70 14 Ld SOIC M14.15

ISL6535IBZ (Note 1

) 6535IBZ -40 to +85 14 Ld SOIC M14.15

ISL6535CRZ (Note 2

) 65 35CRZ 0 to +70 16 Ld 4x4 QFN L16.4x4

ISL6535IRZ (Note 3) 65 35IRZ -40 to +85 16 Ld 4x4 QFN L16.4x4

1. Add “-T” suffix for 2.5k unit tape and reel option. Please refer to TB347

for details on reel specifications.

2. Add “-T” suffix for 6k unit tape and reel option. Please refer to TB347

for details on reel specifications.

3. Add “-T” suffix for 6k unit or -TK for 1k unit tape and reel options. Please refer to TB347

for details on reel specifications.

4. 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.

5. For Moisture Sensitivity Level (MSL), please see product information page for ISL6535

. For more information on MSL, please see tech brief TB363.

Block Diagram

FIGURE 1. BLOCK DIAGRAM

SOFT-START

BOOT

UGATE

GND

AND

FAULT LOGIC

COMP

PGND

LGATE

PWM

PVCC

VCC

GATE

CONTROL

LOGIC

INTERNAL

REGULATOR

OSCILLATOR

30mA

SSDONE

POWER-ON

RESET (POR)

(QFN ONLY)

REFIN

REF

= 0.597V

REFERENCE

(QFN ONLY)

OCSET

200mA

SOURCE OCP

PHASE

6mA

P1-P3 P4-P6 P7-P9 P10-P12 P13-P15

ISL6535CBZ-T

Mfr. #:

Buy ISL6535CBZ-T

Manufacturer:

Renesas / Intersil

Description:

Switching Controllers PWM CNTRLR DDRG 14LD N

Lifecycle:

New from this manufacturer.

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ISL6535CBZ-T

ISL6535CBZ-T

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