Cherry Semiconductor CS5156HGDR16, CS5156HGD16, CS5156GN16, CS5156GDR16, CS5156GD16 Datasheet

The CS5156 is a 5-bit nonsyn­chronous N-Channel buck con­troller. It is designed to provide
unprecedented transient response
for today’s demanding high-densi­ty, high-speed logic. The regulator
operates using a proprietary control
method, which allows a 100ns
response time to load transients.
The CS5156 is designed to operate
over a 4.25-16V range (VCC) using
12V to power the IC and 5V as the
main supply for conversion.

The CS5156 is specifically designed
to power Pentium®II processors

and other high performance core
logic. It includes the following fea­tures: on board, 5-bit DAC, short
circuit protection, 1.0% output tol­erance, VCCmonitor, and pro­grammable soft start capability. The
CS5156 is backwards compatible
with the 4-bit CS5151, allowing the
mother board designer the capabili­ty of using either the CS5151 or the
CS5156 with no change in layout.
The CS5156 is available in 16 pin
surface mount and DIP packages.

Features

■ N-Channel Design

■ Excess of 1MHz Operation

■ 100ns Transient Response

■ 5-Bit DAC

■ Backward Compatible with

4-Bit CS5150/5151 and
Adjustable CS5120/5121

■ 30ns Gate Rise/Fall Times

■ 1% DAC Accuracy

■ 5V & 12V Operation

■ Remote Sense

■ Programmable Soft Start

■ Lossless Short Circuit

Protection

■ V

CC

Monitor

■ Adaptive Voltage

Positioning

■ V

2

™

Control Topology

■ Current Sharing

■ Overvoltage Protection

Package Options

CPU 5-Bit Nonsynchronous Buck Controller

CS5156

Description

Application Diagram

1

V

ID0

V

ID1

V

ID2

V

ID3

SS

V

ID4

C

OFF

V

FFB

V

FB

COMP

LGnd

V

CC1

NC

PGnd
V

GATE

V

CC2

16 Lead SO Narrow & PDIP

1

Switching Power Supply for core logic - Pentium®II processor

0.33µF

V

ID0

V

ID1

V

ID2

V

ID3

V

ID0

V

ID1

V

ID2

V

ID3

V

CC1

SS

C

OFF

LGnd

V

FB

V

FFB

COMP

IRL3103

0.1µF

12V 5V

2µH

1.3V to 3.5V @ 13A

V

CC2

V

GATE

PGnd

1200µF/16V x 3
AlEl

3.3k

0.1µF

1200µF/16V x 5
AlEl

100pF

330pF

V

ID4

V

ID4

CS5156

MBR1535CT

2

1,3

V2is a trademark of Switch Power, Inc.

Pentium is a registered trademark of Intel Corporation.

CS5156

Rev. 1/5/99

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

®

2

Pin Name Max Operating Voltage Max Current

V

CC1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25mA DC/1.5A peak

V

CC2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20mA DC/1.5A peak

SS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-100µA

COMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200µA

VFB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2µA

C

OFF

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2µA

V

FFB

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2µA

V

ID0

- V

ID4

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-50µA

V

GATE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100mA DC/1.5A peak

LGnd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25mA

PGnd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100mA DC/1.5A peak

Operating Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .°0 to 150°C

Lead Temperature Soldering

Wave Solder (through hole styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 sec. max, 260°C peak

Reflow (SMD styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 sec. max above 183°C, 230°C peak

Storage Temperature Range, TS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-65° to 150°C

ESD Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS5156

Electrical Characteristics:

0°C < TA< +70°C; 0°C < TJ< +85°C; 8V < V

CC1

< 14V; 5V < V

CC2

< 14V; DAC Code: V

ID4

= V

ID2

=

V

ID1

= V

ID0

= 1; V

ID3

= 0; CV

GATE

= 1nF; C

OFF

= 330pF; CSS= 0.1µF, unless otherwise specified.

Absolute Maximum Ratings

■ Error Amplifier

V

FB

Bias Current VFB= 0V 0.3 1.0 µA

Open Loop Gain 1.25V < V

COMP

< 4V; Note 1 50 60 dB
Unity Gain Bandwidth Note 1 500 3000 kH
COMP SINK Current V

COMP

= 1.5V; VFB= 3V; VSS> 2V 0.4 2.5 8.0 mA

COMP SOURCE Current V

COMP

= 1.2V; VFB= 2.7V; VSS= 5V 30 50 70 µA

COMP CLAMP Current V

COMP

= 0V; VFB= 2.7V 0.4 1.0 1.6 mA
COMP High Voltage VFB= 2.7V; VSS= 5V 4.0 4.3 5.0 V
COMP Low Voltage VFB=3V 160 600 mV
PSRR 8V < V

CC1

< 14V @ 1kHz; Note 1 60 85 dB

■ V

CC1

Monitor

Start Threshold Output switching 3.75 3.90 4.05 V
Stop Threshold Output not switching 3.70 3.85 4.00 V
Hysteresis Start-Stop 50 mV

■ DAC

Input Threshold V

ID0

, V

ID1

, V

ID2

, V

ID3

, V

ID4

1.00 1.25 2.40 V

Input Pull Up Resistance V

ID0

, V

ID1

, V

ID2

, V

ID3

, V

ID4

25 50 100 kΩ
Pull Up Voltage 4.85 5.00 5.15 V
Accuracy Measure VFB= V

COMP

, 25°C ≤ TJ≤ 85°C 1.0 %

V

ID4VID3VID2VID1VID0

0 1 1 1 1 1.3266 1.3400 1.3534 V
0 1 1 1 0 1.3761 1.3900 1.4039 V
0 1 1 0 1 1.4256 1.4400 1.4544 V
0 1 1 0 0 1.4751 1.4900 1.5049 V
0 1 0 1 1 1.5246 1.5400 1.5554 V

0 1 0 1 0 1.5741 1.5900 1.6059 V
0 1 0 0 1 1.6236 1.6400 1.6564 V

0 1 0 0 0 1.6731 1.6900 1.7069 V
0 0 1 1 1 1.7226 1.7400 1.7574 V

0 0 1 1 0 1.7721 1.7900 1.8079 V

CS5156

3

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Electrical Characteristics:

0°C < TA< +70°C; 0°C < TJ< +85°C; 8V < V

CC1

< 14V; 5V < V

CC2

< 14V; DAC Code: V

ID4

= V

ID2

=

V

ID1

= V

ID0

= 1; V

ID3

= 0; CV

GATE

= 1nF; C

OFF

= 330pF; CSS= 0.1µF, unless otherwise specified.

■ DAC: continued

V

ID4VID3VID2VID1VID0

0 0 1 0 1 1.8216 1.8400 1.8584 V
0 0 1 0 0 1.8711 1.8900 1.9089 V
0 0 0 1 1 1.9206 1.9400 1.9594 V
0 0 0 1 0 1.9701 1.9900 2.0099 V
0 0 0 0 1 2.0196 2.0400 2.0604 V
0 0 0 0 0 2.0691 2.0900 2.1109 V
1 1 1 1 1 1.2315 1.2440 1.2564 V
1 1 1 1 0 2.1186 2.1400 2.1614 V
1 1 1 0 1 2.2176 2.2400 2.2624 V
1 1 1 0 0 2.3166 2.3400 2.3634 V
1 1 0 1 1 2.4156 2.4400 2.4644 V
1 1 0 1 0 2.5146 2.5400 2.5654 V
1 1 0 0 1 2.6136 2.6400 2.6664 V
1 1 0 0 0 2.7126 2.7400 2.7674 V
1 0 1 1 1 2.8116 2.8400 2.8684 V
1 0 1 1 0 2.9106 2.9400 2.9694 V
1 0 1 0 1 3.0096 3.0400 3.0704 V
1 0 1 0 0 3.1086 3.1400 3.1714 V
1 0 0 1 1 3.2076 3.2400 3.2724 V
1 0 0 1 0 3.3066 3.3400 3.3734 V
1 0 0 0 1 3.4056 3.4400 3.4744 V
1 0 0 0 0 3.5046 3.5400 3.5754 V

■ V

GATE

Out SOURCE Sat at 100mA Measure V

CC2

– V

GATE

1.2 2.0 V

Out SINK Sat at 100mA Measure V

GATE

– VPGnd; 1.0 1.5 V

Out Rise Time 1V < V

GATE

< 9V; V

CC1

= V

CC2

= 12V 30 50 ns

Out Fall Time 9V > V

GATE

> 1V; V

CC1

= V

CC2

= 12V 30 50 ns
Shoot-Through Current Note 1 50 mA
V

GATE

Resistance Resistor to LGnd 20 50 100 kΩ

V

GATE

Schottky LGnd to V

GATE

@ 10mA 600 800 mV

■ Soft Start (SS)

Charge Time 1.6 3.3 5.0 ms
Pulse Period 25 100 200 ms
Duty Cycle (Charge Time/Pulse Period) × 100 1.0 3.3 6.0 %
COMP Clamp Voltage VFB= 0V; VSS= 0 0.50 0.95 1.10 V
V

FFB

SS Fault Disable V

GATE

= Low 0.9 1.0 1.1 V

High Threshold 2.5 3.0 V

■ PWM Comparator

Transient Response V

FFB

= 0 to 5V to V

GATE

= 9V to 1V; 100 125 ns

V

CC1

= V

CC2

= 12V

V

FFB

Bias Current V

FFB

= 0V 0.3 µA

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

4

CS5156

Package Pin Description

PACKAGE PIN # PIN SYMBOL FUNCTION

Electrical Characteristics:

0°C < TA< +70°C; 0°C < TJ< +85°C; 8V < V

CC1

< 14V; 5V < V

CC2

< 14V; DAC Code: V

ID4

= V

ID2

= V

ID1

= V

ID0

= 1; V

ID3

= 0; CV

GATE

= 1nF; C

OFF

= 330pF; CSS= 0.1µF, unless otherwise specified.

■ Supply Current

I

CC1

No Switching 8.5 13.5 mA

I

CC2

No Switching 1.6 3.0 mA

Operating I

CC1

VFB= COMP = V

FFB

813mA

Operating I

CC2

VFB= COMP = V

FFB

25 mA

■ C

OFF

Normal Charge Time V

FFB

= 1.5V; VSS= 5V 1.0 1.6 2.2 µs

Extension Charge Time VSS= V

FFB

= 0 5.0 8.0 11.0 µs

Discharge Current C

OFF

to 5V; V

FB

>1V 5.0 mA

■ Time Out Timer

Time Out Time VFB= V

COMP

; V

FFB

= 2V; 10 30 50 µs

Record V

GATE

Pulse High Duration

Fault Mode Duty Cycle V

FFB

= 0V 35 50 65 %

Note 1: Guaranteed by design, not 100% tested in production.

16L SO Narrow & PDIP

1,2,3,4,6 V

ID0

– V

ID4

Voltage ID DAC input pins. These pins are internally pulled up to 5V
providing logic ones if left open. V

ID4

selects the DAC range. When V

ID4

is High (logic one), the DAC range is 2.14V to 3.54V with 100mV incre­ments. When V

ID4

is Low (logic zero), the DAC range is 1.34V to 2.09V

with 50mV increments. V

ID0

- V

ID4

select the desired DAC output volt­age. Leaving all 5 DAC input pins open results in a DAC output voltage
of 1.244V, allowing for adjustable output voltage, using a traditional
resistor divider.

5 SS Soft Start Pin. A capacitor from this pin to LGnd in conjunction with

internal 60µA current source provides soft start function for the con­troller. This pin disables fault detect function during Soft Start. When a
fault is detected, the soft start capacitor is slowly discharged by internal
2µA current source setting the time out before trying to restart the IC.
Charge/discharge current ratio of 30 sets the duty cycle for the IC when
the regulator output is shorted.

7C

OFF

A capacitor from this pin to ground sets the time duration for the on
board one shot, which is used for the constant off time architecture.

8V

FFB

Fast feedback connection to the PWM comparator. This pin is connected
to the regulator output. The inner feedback loop terminates on time.

9V

CC2

Boosted power for the gate driver.

10 V

GATE

MOSFET driver pin capable of 1.5A peak switching current.

5

CS5156

Block Diagram

Q

V

ID1

V

CC1

SS

COMP

V

FB

V

ID0

LGnd

V

FFB

V

CC2

V

GATE

PGnd

V

ID2

V

ID3

-

+

5 BIT

DAC

C

OFF

Slow Feedback

Maximum

On-Time

Timeout

R

Q

S

C

OFF

One Shot

PWM
COMP

SS High
Comparator

FAULT

Latch

2.5V

Error
Amplifier

Fast Feedback

-

+

V

CC1

Monitor

Comparator

V

ID4

-

+

-

+

-

+

-

+

V

FFB

Low

Comparator

PWM
Comparator

SS Low
Comparator

R

Q

S

Q

R

Q

S

2µA

5V

60µA

Normal

Off-Time

Timeout

Extended

Off-Time

Timeout

Time Out

Timer

(30µs)

Edge Triggered

Off-Time

Timeout

3.90V

3.85V
FAULT

FAULT

GATE = ON

GATE = OFF

PWM
Latch

1V

0.7V

Package Pin Description: continued

PACKAGE PIN # PIN SYMBOL FUNCTION

16L SO Narrow & PDIP

11 PGnd High current ground for the IC. The MOSFET driver is referenced to

this pin. Input capacitor ground and the anode of the Schottky diode
should be tied to this pin.

12 NC No connection.

13 V

CC1

Input power for the IC.

14 LGnd Signal ground for the IC. All control circuits are referenced to this pin.

15 COMP Error amplifier compensation pin. A capacitor to ground should be

provided externally to compensate the amplifier.

16 V

FB

Error amplifier DC feedback input. This is the master voltage feedback
which sets the output voltage. This pin can be connected directly to the
output or a remote sense trace.