Datasheet SC1151CS.TR Datasheet (Semtech Corporation)

SC1151

© 1998 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

PROGRAMMABLE DC/DC CONTROLLER
FOR ADVANCED MICROPROCESSORS

March 11, 1998

1

ABSOLUTE MAXIMUM RATINGS

Parameter Symbol Maximum Units

VCC to GND V

IN

-0.3 to 7 V

PGND to GND ± 1 V

BST to GND -0.3 to 15 V

Operating
Temperature Range

T

A

0 to 70 °C

Storage
Temperature Range

T

STG

-65 to +150 °C

Lead Temperature
(Soldering) 10 sec

T

LEAD

300 °C

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DESCRIPTION

The SC1151 voltage mode controller contains most of
the circuitry necessary to implement a DC/DC con­verter for powering advanced microprocessors such
as Klamath, both in single and multiple processor con­figurations.

The SC1151 features an integrated 5 bit D/A con­verter, pulse by pulse current limiting, integrated
power good signaling, logic compatible shutdown and
on-board over voltage protection (OVP).

The SC1151 operates at a fixed frequency of 200kHz,
providing an optimum compromise between size, effi­ciency and cost in the intended application areas.

The integrated D/A converter provides programmabil­ity of output voltage from 2.0V to 3.5V in 100mV in­crements and 1.80V to 2.05V in 50mV increments with
no external components.

The SC1151 provides an OVP output which can be
used to trigger a crowbar circuit for true over voltage
protection.

APPLICATIONS

• Klamath microprocessor supplies

• Klamath VRM modules

• 1.8V to 3.5V microprocessor supplies

• Programmable power supplies

FEATURES

• 85% efficiency

• 5 bit DAC for output programmability

• On chip power good and OVP functions

• Designed for Intel Klamath VRM8.1 requirements

ORDERING INFORMATION

DEVICE

(1)

PACKAGE TEMP RANGE (TJ)

SC1151CS SO-16 0° to 125°C

BLOCK DIAGRAM

VCC

VCC

ERROR
AMP

D/A AND
SHUTDOWN
LOGIC

DECODED SHUTDOWN SIGNAL

OSCILLATOR

LEVEL SHIFT
AND DRIVE

1.25V REF

+

-

+

-

CURRENT LIMIT

+

-

+

-

CSm

VID0

VID2
VID1

VID3

VOSENSE

PWRGOOD

BST

DH

VCC

SHUTDOWN

OVP

GND

PGND

R

S

Q

+

-

70mV

CSp

+

-

VID4

A17043A

PIN CONFIGURATION

1
2
3
4
5
6
7
8

16
15
14
13
12
11
10

9

PWRGOOD

VID0
VID1
VID2
VID3

BSTDH

VOSENSE

GND

SHUTDOWNPGND

VCC

CSp

CSm

OVP

VID4

Note:
(1) Add suffix ‘TR’ for tape and reel.

SC1151

© 1998 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

PROGRAMMABLE DC/DC CONTROLLER
FOR ADVANCED MICROPROCESSORS

March 11, 1998

2

NOTES:

(1) Low output currents, below the continuous conduction threshold will cause an increase in output voltage beyond
the load regulation limit. For Application circuit 16935F see the regulation curve on sheet 5.
(2) All VID codes not specifically listed here are invalid and cause shutdown exactly as if the shutdown pin had been
asserted. xxxxx refers to any valid VID code.

ELECTRICAL CHARACTERISTICS

Unless specified: VCC = 4.75V to 5.25V; GND = PGND = 0V; V

OSENSE

= VO; 0mV < (CSp-CSm) < 60mV; TA = 25oC

PARAMETER CONDITIONS VID

43210

MIN TYP MAX UNITS

Output Voltage

(2)

IO = 2A in Application circuit 16935F 00101 1.782 1.800 1.818 V

00100 1.832 1.850 1.868
00011 1.881 1.900 1.919
00010 1.931 1.950 1.969
00001 1.980 2.000 2.020
00000 2.030 2.050 2.070
11111 1.980 2.000 2.020
11110 2.079 2.100 2.121
11101 2.178 2.200 2.222
11100 2.277 2.300 2.323
11011 2.376 2.400 2.424
11010 2.475 2.500 2.525
11001 2.574 2.600 2.626
11000 2.673 2.700 2.727
10111 2.772 2.800 2.828
10110 2.871 2.900 2.929
10101 2.970 3.000 3.030
10100 3.069 3.100 3.131
10011 3.168 3.200 3.232
10010 3.267 3.300 3.333
10001 3.366 3.400 3.434
10000 3.465 3.500 3.535

Load Regulation IO = 0.3A to 13A

(1)

xxxxx 1 %
Line Regulation xxxxx 0.5 %
UV Lockout xxxxx 4.2 V
Current Limit Voltage xxxxx 60 70 80 mV
Oscillator Frequency xxxxx 180 200 220 kHz
Oscillator Max Duty Cycle xxxxx 90 95 %
DH Sink/Source Current BST - DH = 4.5V, DH - PGND = 2V xxxxx 1 A
Output Voltage Tempco xxxxx 65 ppm/oC

SC1151

© 1998 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

PROGRAMMABLE DC/DC CONTROLLER
FOR ADVANCED MICROPROCESSORS

March 11, 1998

3

NOTE:

(1) All logic level inputs and outputs are
open collector TTL compatible

PIN DESCRIPTION

Pin # Pin Name Pin Function

1

GND

Small Signal Analog and Digital Ground

2

V

CC

Chip Supply Voltage

3

OVP

High Signal out if VO>setpoint + 20%

4

PWRGOOD

(1)

Open collector logic output, high if VO within
10% of setpoint

5

CSm

Current Sense Input (negative)

6

CSp

Current Sense Input (positive)

7

PGND

Power Ground

8

DH

High Side Driver Output

9

BST

Vcc for High Side Driver

10

SHUTDOWN

(1)

Logic low shuts down the converter

11

V

OSENSE

Top end of internal feedback chain

12

VID4

(1)

Programming Input (MSB)

13

VID3

(1)

Programming Input

14

VID2

(1)

Programming Input

15

VID1

(1)

Programming Input

16

VID0

(1)

Programming Input (LSB)

1
2
3
4
5
6
7
8

16
15
14
13
12
11
10

9

PWRGOOD

VID0
VID1
VID2
VID3

BSTDH

VOSENSE

GND

SHUTDOWNPGND

VCC

CSp

CSm

OVP

VID4

SC1151

© 1998 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

PROGRAMMABLE DC/DC CONTROLLER
FOR ADVANCED MICROPROCESSORS

March 11, 1998

4

MATERIALS LIST

APPLICATION CIRCUIT

C12

0.1uF

C1

0.1uF

C5
1000uF

+

C6
1000uF

+

C7
1000uF

+

C8
1000uF

+

Q1

BUK556

C4

1000uF

+

C3

1000uF

+

C2

1000uF

+

L1

4uH

R2
10k

R3 2.32k

R4

1.00k

C9
1000uF

+

C10
1000uF

+

R1
5mOhm

D1

PSR16C30CT

U1

SC1151CS

GND

1

VCC

2

OVP

3

PWRGOOD

4

CSm

5

CSp

6

PGND

7

DH

8

BST

9

SHUTDOWN

10

VOSENSE

11

VID4

12

VID3

13

VID2

14

VID1

15

VID0

16

R5
10

C13

0.1uF

C11

0.1uF

REF 16935F

5V IN

12V IN

OVP
VID0
VID1
VID2
VID3
VID4

SHUTDOWN
PWRGD

VCCP

Quantity Reference Part/Description Vendor Notes

4 C1,C11-C13 0.1µF Ceramic Various
9 C2-C10 1000µF/6.3V SANYO MV-GX or equiv. Low ESR
1 D1 PSR16C30CT PHOTRON
1 L1 4µH 8 Turns 16AWG on MICROMETALS T50-52D core
1 Q1 BUK556 PHILIPS

Logic level FET, ≤22mΩ, 30V

1 R1

5mΩ

IRC OAR-1 Series

1 R2

10kΩ, 5%, 1/8W

Various

1 R3

2.32kΩ, 1%, 1/8W

Various

1 R4

1kΩ, 1%, 1/8W

Various

1 R5

10Ω, 5%, 1/8W

Various

1 U1 SC1151CS SEMTECH

SC1151

© 1998 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

PROGRAMMABLE DC/DC CONTROLLER
FOR ADVANCED MICROPROCESSORS

March 11, 1998

5

-0.020

-0.010

0.000

0.010

0.020

0.030

0.040

0.050

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0

Voltage change (V) normalized at Io=2A

Output Current (Amps)

SC1151 Regulation in Application circuit 16935F

Application circuit 16935F Ripple, 3.1V, 10A out

70.0%

75.0%

80.0%

85.0%

90.0%

95.0%

100.0%

0.0 2.0 4.0 6.0 8.0 10.0 12.0

14.0

3.50V Set

3.00V Set

2.40V Set

2.00V Set

Efficiency

Output Current (Amps)

SC1151 Efficiency in Application circuit 16935F

Application circuit 16935F Transient Response, 3.1V, 0.3A to 10A

Vo at Io=300mA steady state

Vo at Io=10A steady state

Steady state voltage
levels are superimposed
for reference.

CHARACTERISTIC CURVES

SC1151

© 1998 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

PROGRAMMABLE DC/DC CONTROLLER
FOR ADVANCED MICROPROCESSORS

March 11, 1998

6

OUTLINE DRAWING SO-16

LAND PATTERN SO-16