Datasheet SC1146CSW.TR Datasheet (Semtech Corporation)

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

SC1146

July 25, 2000

TEL:[phone] FAX:[phone] WEB:http://www.semtech.com

DESCRIPTION

The SC1146 is the latest, high performance, multi­phase (PWM) controller designed for high power mi­croprocessors requiring ultra fast transient response.
The SC1146 is programmable for the voltage range
required by the latest Microprocessors . Utilizing a
novel and unique design, the controller distributes the
output load across (up to) four converter channels by
digitally phase shifting the PWM outputs. This ap­proach greatly reduces the stress and heat on the out­put stage components while lowering input ripple cur­rent by as much as 80%. Accurate current sharing
among the four phases is achieved by precision design
techniques and trimming of critical elements.

The high speed transconductance error amplifier is ex­ternally initialized using a soft-start capacitor allowing
the controller to “wake-up” without overshoot, thus pro­tecting the low voltage microprocessor loads. The out­put drive voltage to the power MOSFETs is pro­grammable to minimize switching losses in the drive
circuitry.

The output voltage is digitally programmable by means
of a 5 bit DAC (new codes). A single resistor programs
the master clock frequency (8MHz max) or the clock
can be supplied by an external source where exact fre­quency control is desired. The number of operating
phases is programmed independently of the external
clock. The parts features under-voltage lock-out with
hysteresis and over-current protection.

FEATURES

•= Allows use of small surface mount components

•= Ultra fast transient recovery time

•= Dramatic reduction of input ripple current and out-

put ripple voltage

•= 5-bit programmable DAC for the latest, lower

output voltage Microprocessors

•= Wide, High frequency operating range

•= Selectable 2, 3, 4 phase operation

•= +5 Volt only operation eliminates the need for

+12V supply

•= Precision load current sharing,1%PWM match

•= Selectable internal or external clock

•= Soft start/UVLO/Over current protection

APPLICATIONS

•= High end servers and workstations

•= High current/Ultra-fast transient microprocessors

ORDERING INFORMATION

DEVICE

SC1146CSW.TR SO-24 0 - 85°C
Note:

(1) Only available in tape and reel packaging. A reel
contains 1000 devices.

(1)

PACKAGE TEMP. (TJ)

BLOCK DIAGRAM

PIN CONFIGURATION

Top View

(24-Pin SOIC)

The SC1146 is patent pending

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

Pentium is a registered trademark of Intel Corporation

1

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

SC1146

July 25, 2000

ABSOLUTE MAXIMUM RATINGS

Parameter Symbol Limits Units

to GND V

V

CC5V

cc5v

-0.3 to + 12 V

FBG to GND FBG ± 1 V

to GND V

V

CC2

Operating Temperature Range T
Junction Temperature Range T
Storage Temperature Range T
Thermal Resistance Junction to Case
Thermal Resistance Junction to Ambient
Lead Temperature (Soldering) 10 sec T

cc2

STG

θ

JC

θ

JA

LEAD

A

J

-0.3 to +20 V
0 to +70 °C

0 to +125 °C

-55 to +150 °C
25 °C/W
80 °C/W

300 °C

ELECTRICAL CHARACTERISTICS

Unless otherwise noted: TA = 25°C, V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V
UVLO Range V
UVLO Hystersis V

CC 5V

CC2

CC5V

CC5V

= 5V, V

= 5V, 4-Phase operation.

CC2

3.9 5.0 15.0 V

3.9 5.0 6.0 V
TBD mV

Supply Voltage Range V
Supply Current V
Supply Current V
Reference Current Pin Voltage V
VID0-4 Clock Select & Divide V
Select Logic Threshold V
VID0-4 Clock Select & Divide I
Select Input Bias Current I
Enable Pin V

Maximum Duty Cycle D
DRV0-3 Output Voltage V

DRV0-3 Source Current I
DRV0-3 Sink Current I

The SC1146 is patent pending

CC5V

CC5V

V

V

SRC

SNK

CC2

REF

INL

INH

INL

INH

INL

INH

MAX

OL

OH

4.5 5.0 5.5 V

DRV Outputs open 10 mA

V

= 2.00V, I

OUT

= 0 40 mA

O

Iref = 250µA 2.05 V

Logic Low 0.8 V

Logic High 2 V

Vid0-4 = 0V -20 µA

Vid0-4 = 4.5V +50 µA

2V

FB = 0V 75 %

I

= 1mA .3 V

sink

I

= 1mA, PWRGOOD = V

source

V

= 2.00V 40 mA

OUT

V

= 2.00V 20 mA

OUT

cc5vVCC2

-1 V

.8 V

2

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

SC1146

July 25, 2000

ELECTRICAL CHARACTERISTICS (Cont.)

Unless otherwise noted: TA = 25°C, V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC5V

= 5V, V

= 5V, 4-Phase operation.

CC2

Bgout Voltage V
Bgout Impedance R
External Clock Freq. Range F

Oscillator Frequency F
Internal Clock Freq. Range F
Match DRV0-3

Bgout

O_Bg

ext_CK

OSC

int_CK

∆=

D

Vid = 00000 TBD 1.30 TBD V

3

KΩ

.80 8.0 8.5 MHz

Iref = 250µA 7.6 8.0 8.4 MHz

.80 8.0 8.5 MHz

Duty cycle (Avg) = 50% -1 +1 %

PWM Off Time Toff 25 %

Overcurrent Comparator,

OCC_CMR 3 15 V
Comparator, Common Mode
Range

OC+I/P bias Current IB_OC+ Vin = 5V +75 +250
OC-I/P bias Current IB_OC- Vin = 5V +75 +250

µΑ

µΑ
Input Offset Voltage VOS_OCC Vin = 5V 10 mV
Feedback Input Impedance Ri_FB V

= 2.00V 12

O

ΚΩ

Duty Cycle Range D 0 75 %

CONVERTER SPECIFICATIONS, Reference Application Circuit

Output Accuracy Over Set

V

OUT

VID 0-4 = 0000-1111

Range
Load Regulation V

Line Regulation V

∆

OUT

IV∆

O

∆

VV∆

OUT

IN

V

IN

Vcc5v) I

I

= 5V, VO = 2.000V

CC5V

= 4-6V, (V

O

= 5.0V

V

CC5V

= 2.000V

O

= 3A - 20A

O

separated from

IN

= 5A , Clk = external

-1 +1 %

.025 .05 %/A

%/V

.15

POWER GOOD SIGNAL

Off Leakage Current I
Power Good Max Sink Current I
Power Good Threshold P
Voltage Tolerance P

leakage_Off

Sink_Max

wrgood_T_lo

wrgood_T_Hi

PWRGOOD = Logic High 2 µA

PWRGOOD< = .8V 2 mA
Vout = 1.300V - 1.950V + 100 mV
Vout = 2.000V - 3.500V + 150 mV

Note:
(1) This device is ESD sensitive. Use of standard ESD handling precautions is required.

The SC1146 is patent pending

3

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

July 25, 2000

PIN DESCRIPTION

Pin # Pin Name Pin Function

SC1146

1V

CC 5V

Supply voltage input (5V nominal)

2 Divsel Connect to Gnd for four phase operation and to logic High for three Phase

operation.

3 Clksel Clock Select: Logic High selects internal clock. Logic Low selects external

clock.

4 Extclk External Clock Input. The output frequency is determined by (Clock Input

Freq.)/4. Output freq.= (Clock Input)/4. Pull up to Vcc5v to select internal
clock.

5R

REF

Connects to external reference resistor. Sets the operating frequency of
the internal clock and the ramp time for the PWM. Reference voltage at

this pin is 2.05V. Trimmed to set 250µA at 8MHz.
6VID0
7VID1
8VID2

9VID3

10 VID4

(1)

(1)

(1)

(1)

(1)

Programming Input (LSB)

Programming Input

Programming Input

Programming Input

Programming Input (MSB)

11 OC+ Over current comparator. Non-Inverting input.
12 OC- Over current comparator. Inverting input.
13 COMP Compensation Pin. Compensation is acheived by connecting a capacitor in

series with a resistor between this pin and FBG. A 300K ohm resistor

must also be directly connected between this pin and FBG.

14 FB Feedback input connected to supply output.
15 BG

OUT

Bandgap Reference Output. Output resistance = 3Kohm. Must be

bypassed with 4.7nF-100nF capacitor to FBG. This capacitor programs the

soft start time.

16 FBG Feedback Ground. This pin must be connected to return side of output

caps. This pin is not internally connected to GND.

17 ENABLE Connects to 5V to ENABLE. Connect to GND to disable entire device.
18 GND Ground Pin
19 DRV2 Phase 2 output, output voltage range ~.3V - V
20 DRV0 Phase 0 output, output voltage range ~.3V - V

CC2

CC2

- 1V.

- 1V.

21 VCC2 Supply voltage for the DRV0-3, may be connected to +5V or +12V supply.

There is no Undervoltage Lockout on this pin.

22 DRV1 Phase 1 output, output voltage range ~.3V - V
23 DRV3 Phase 3 output, output voltage range ~.3V - V

CC2

CC2

- 1V.

- 1V.

24 PWRGOOD Power good should be pulled-up to 5V supply via a 3K - 10K resistor.

NOTE: (1) All logic inputs and outputs are open collector TTL compatible.

The SC1146 is patent pending

4

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

July 25, 2000

OUTPUT VOLTAGE

Unless specified: 0 = GND; 1 = High (or Floating).

= 25°C, V

T

A

VID4 VID3 VID2 VID1 VID0 (VDC)

CC5V

= 5V, V

= 5V, 4-Phase operation.

CC2

1 1 1 1 1 Output Off
11 1 1 01.1
1 1 1 0 1 1.125
11 1 0 01.15
1 1 0 1 1 1.175
11 0 1 01.2
1 1 0 0 1 1.225
1 1 0 0 0 1.250
1 0 1 1 1 1.275
10 1 1 01.3
1 0 1 0 1 1.325
10 1 0 01.35
1 0 0 1 1 1.375
10 0 1 01.4
1 0 0 0 1 1.425
10 0 0 01.45
0 1 1 1 1 1.475
01 1 1 01.5
0 1 1 0 1 1.525
01 1 0 01.55
0 1 0 1 1 1.575
01 0 1 01.6
0 1 0 0 1 1.625
01 0 0 01.65
0 0 1 1 1 1.675
00 1 1 01.7
0 0 1 0 1 1.725
00 1 0 01.75
0 0 0 1 1 1.775
00 0 1 01.8
0 0 0 0 1 1.825
00 0 0 01.85

SC1146

V

CCCORE

The SC1146 is patent pending

5

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

The SC1146 is patent pending

J1

1
2
3

1u,16V

4
5

C12

C11

6

INPUT

S1

9
10
11
12
13
14
15
16

Vout/Clk switch

JMP1

ENSYN

BY JUMPERING JMP1, ALL SC1405'S ARE ENABLED AND
DISABLED TOGETHER WITH SC1144. THREE OF THE SC1405'S
CAN BE DIRECTLY CONTROLLED BY SEPARATING THE TWO
ENABLES. (power saving mode)

6

+12V

.1uC7

C8

330UF,16V

1u,16V

C13

8
7
6

EN

5
4
3
2
1

10uf,6.3v

TBD

100

R18

R19

.01
C45

Freq. set by R22
Freq.=(8.2K/R22)*2Mhz per
Phase

R4
10K

10K

R33

SMOD

10
R1

1

R6

R5

R7

2

10K

10K

10K

3

4

5

6

7

8

9

10 15

11 14

12

sel
R22

.1
C46

Long PCB Trace

Power Good

5v

Divsel

Clksel

Extclk

Rref

Vid0

Vid1

Vid2

Vid3

Vid4 Bgout

OC+ FB

OC-

SC1146
U2

Pwrgood

Drv3

Drv1

Vcc2

Drv0

Drv2

GND

Enable

FBG

Comp

July 25, 2000

EVALUATION BOARD SCHEMATIC

D1

D2

SS12D3SS12D4SS12

SS12

.1uC2

.1uC3

.1uC4

.1uC5

JMP2

3k

R32

24

22

23

R9

22

22

R8

21

22

20

R11
22

19

R13

18

EN

17

Open
R15

16

VOUT

13

10K

.1u

R20

C42

.001

open

C43

R24

R25

2.2

.1u
C47

.1uC14.1uC23.1uC32.1uC41

EN

47pf
C16

47pf
C26

47pf

C37

1
R21

47pf
C44

U1

8

BST

Vcc

3

GND

PRDY
EN

DRN
CO
DELAY_C
OVP_S

DSPS_DR

S_MOD PGND

SC1405B

U3

Vcc
GND

PRDY

DRN

EN
CO
DELAY_C
OVP_S

DSPS_DR

S_MOD PGND

SC1405B

U4

Vcc
GND

PRDY
EN

DRN
CO
DELAY_C
OVP_S

DSPS_DR

S_MOD PGND

SC1405B

U5

Vcc
GND

PRDY

DRN

EN
CO
DELAY_C
OVP_S

DSPS_DR

S_MOD PGND

SC1405B

TG

BG

BST

TG

BG

BST

TG

BG

BST

TG

BG

7
2
4
6
1

5 10

8
3

7
2
4
6
1

5 10

8
3

7
2
4
6
1

5 10

8
3

7
2
4
6
1

5 10

14
13

12
9

11

14

13
12
9

11

14
13

12
9

11

14

13
12

9

11

R28

0

.1u

R29

0

.1u

R30

0

R31

0

.1u C50

.1u
C49

FDP6035

R2

Q1

.1u

C9

C22

C31

.1u C40

0

Q2
R3
0

FDB7030

.1u

10u,16V

C18

.1u

C27

.1u

C35

C19

R10

0

R12
0

10u,16V
C28

R14

0
R16

0

10u,16V
C36

R17

R23

0

FDP6035

Q3

Q4

FDB7030

FDP6035

Q5

Q6

FDB7030

FDP6035

Q7

0

Q8
FDB7030

PID1103-1u

D5

30BQ015

PID1103-1u

D6

30BQ015

PID1103-1u

D7

30BQ015

PID1103-1u

D8

30BQ015

22u,10V
C1

22u,10V
C6

22u,10V
C10

L1

22u,10V
C15

22u,10V
C17

22u,10V
C20

22u,10V

L3

C21

VRM9.0 PROGRAMMABLE, MULTI-PHASE,

22u,10V
C24

VOUT

22u,10V
C25

22u,10V
C29

22u,10V

L5

C30

22u,10V
C33

22u,10V
C34

22u,10V
C38

L7

C39
1000uf,6.3

C51
1000uf,6.3

HIGH PERFORMANCE PWM CONTROLLER

*

.1
TBD
R27

*

0
R26

C48

R26 AND R27 SET THE OVERVOLTAGE TRIP

SC1146

POINT. C48 SETS THE TIME CONSTANT.
R27=0,R26=OPEN to disable OVP_S.

Shipped with OVP_S disabled

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

SC1146

July 25, 2000

BILL OF MATERIAL
Item Qty Reference Value Manufacturer

1 9 C2,C4,C11,C19,C20,C28,C29,C37,C39 1u,10V X7R, AVX [phone]
2 1 C3 10uF, 6.3V Al. Elec.,Murata
3 9 C5,C12,C14,C17,C18,C21,C22,C26,C27 22u, 10V Murata [phone]

PN #GRM235Y5V226Z010
4 5 C6,C7,C15,C24,C32 1uF, 16V Murata,Al. Elec.
5 1 C8 330uF, 16V Nichicon
6 3 C16,C25,C33 10u, 16V Murata
7 1 C40 .01u Murata
8 1 C42 .022 any
9 2 C45,C49 .01 Murata,X7R

10 1 C46 .001 Murata
11 4 C50,C51,C52,C53 1nF any
12 1 C54 1000uF Murata,Al. Elec.
13 8 D1,D2,D3,D4,

D5,D7,D9,D11

14 1 J1 INPUT
15 4 L1,L2,L3,L4 .6uh,12A Falco [phone]

16 4 Q1,Q4,Q7,Q10 IR7811 Int. Rectifier
17 4 Q3,Q6,Q9,Q12 IR3101D2

18 1 R1 10 Dale,any
19 9 R2,R10,C13,R14,R17,C23,R33,C34,C43 0 any
20 4 R4,R12,R16,R23 1.5 (or zero) any
21 4 R5,R6,R7,R38 10K any
22 4 R8,R9,R11,R13 22 any
23 1 R18 SEL any
23 1 R19 100 any
24 1 R20 2.2k any
25 1 R22 15k any
26 1 R24 300k any
27 5 R25,R40,R41,R42,R43 2.2 any
28 1 R26 open any
29 4 R27,R28,R29,R30 51, 1/4W, 1206, 10K Dale
30 6 R31,R32,R34,R35,R36,R37 TBD(used at light load,

31 1 S1 Vout/Clk switch C&K (800)cal-swch
32 4 U1,U3,U4,U5 SC1405B/SC1405TS Semtech [phone]
33 1 U2 SC1146CSW Semtech [phone]
34 1 U6 LM358 any

Unless otherwise noted, all resistors are 1/10W, 5%, 0805 and all capacitors are 20%, 50v, 0805.

SS12(1A)

SS32 (3A)

(Alter.)FDB7030BL

contact factory)

General Instruments

General Instruments

PN #T02508

Int. Rectifier

Fairchild Semiconductors

any

The SC1146 is patent pending

7

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

July 25, 2000

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

SC1146

THEORY OF OPERATION

FUNCTIONAL DESCRIPTION

The SC1146 is a programmable, high performance,
multi-phase controller designed for the most demand­ing DC/DC converter applications in which transient
response, space, input ripple current and component
form factor and cost are paramount. The SC1146 is
configured to operate with external MOSFET drivers,
such as the SC1405, in high efficiency synchronous
applications (See Evaluation Board Schematic).
The SC1146 based dc/dc converter consists of four
buck converter controllers integrated and synchro­nized. The high clock frequency allows for smaller in­ductor values and miniature surface mount, low induc­tance output capacitors. Since each stage has ¼ the
output current, the conduction losses in each stage is
reduced by a factor of 1/16. Precision active trimming
ensures 1% matching of duty cycles among phases,
thus ensuring the heat and component stress is shared
equally. The SC1146 may also be configured in asyn­chronous mode by using buffer transistors.

ables the PWM controller sequentially. A resistor from

pin to FBG programs the frequency and ramp time.

R

REF

Clock Freq = (8.2K/Rref) *8Mhz
The ramps are then compared to the error amplifier out-

put at the high speed PWM comparator inputs. The con­troller outputs are buffered versions of the comparator
outputs.

Fig. 1: V

Ripple, V

OUT

= 1.0V, I

OUT

OUT

= 30A

DECODER/BIAS GENERATOR/PWM CONTROLLER

The 8 MHz clock is divided down to 2 MHz for four
phase operation by the clock decoder. The start of the
output pulses are time shifted 90 degrees by the de­coder with respect to each other. The Bias Generator
generates the ramps to each phase by a precision
trimmed current source and on-chip capacitors. The
decoder, which is synchronized to the bias generator
via the master clock, phase shifts the ramps and en-

Fig. 2: The four Gate Drives firing 90° out of phase.
V

= 1.0V, I

OUT

= 10A,Vcc2=12V, Asynchronous

OUT

operation.

ERROR AMPLIFIER

At the heart of the controller is an ultra-fast, transcon­ductance error amplifier. Since the output inductor val­ues can be selected to be a minimum, usually less than
a micro-Henry, the delays due to inductor ramp time are
minimized during transient load recovery. The higher
frequency of operation also allows use of much smaller
capacitance on the output. This means that the dc/dc
converter output capacitors “hold time” is less. The error
amplifier must therefore respond extremely fast
“Recover the Fort” after a transient. The SC1146 error
amplifier recovers to its normal duty cycle after applica­tion of a full load transient within 2 usec maximum,
(largely dependant on supply quality) and usually within
1usec. This minimizes undershoot and overshoot during
application of a transient.

The SC1146 is patent pending

8

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

July 25, 2000

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

SC1146

ERROR AMPLIFIER CONT.

Fig. 3: Transient response, Top trace, Current sense
8A/div @ 30A/usec. Bottom trace, V

OUT

.

BANDGAP REFERENCE/SOFT START

The precision internal bandgap reference provides a
stable, temperature compensated 2.05 V reference for
the error amplifier’s non-inverting input, the DAC

REF

for
the VID digital to analog converter, the under-voltage
lock-out circuitry as well as the reference for the Bias
generator current sources. The error amplifiers non­inverting input is connected to the bandgap reference
through a 3Kohm resistor, which is also externally con­nected to a soft-start capacitor via the BG

pin. Upon

OUT

application of power, the non-inverting input of the er­ror amplifier is held low for a short time, set by the RC
product of the soft-start capacitor and 3Kohm, allowing
for the decoder and PWM controller to settle. This pre­vents any harmful output voltage overshoots upon start
up or after a converter shut-down (as a result of over­current or the enable pin pulled low). The non-inverting
input then ramps up according to the RC time constant
allowing gradual rise of output voltage.

OVER-CURRENT COMPARATOR

The SC1146 has an internal over-current comparator
designed to sense current in the input supply path.
The comparator inputs have a high common voltage
range thus allowing operation under all possible volt­age/current combinations. The output of the compara­tor pulls the BG

(soft start) pin low thus disabling the

OUT

error amplifier and causing the PWM outputs to enter
minimum duty cycle mode, regulating the output at a
minimum voltage. A current sense trace may be used
as the current sense resistor. This will utilize the trace
as input filter inductor, thus preventing conducted
emissions to input supply. For details of programming
the overcurrent comparator, refer to SC1144-EVB user
manual.

Fig. 4: Transient response, Top trace, Gate Drive

SC1146 Special features:

Bottom trace, Transient current 16A/div @ 30A/usec.

The SC1146 is a special version of the original
SC1144, 4-phase PWM controller, with the latest

The error amplifier has two inverting inputs, one for the
High Range, (VID4 set to logic high) and one input for
the Low Range. The effective gain of the error ampli­fier stays constant in both ranges keeping the loop gain
constant regardless of output voltage range.

VRM9.0 VID codes which allow programming lower
output voltages required by the latest Microprocessors.
Also a +12V supply is no longer required. The V

CC2

and
PWRGOOD pins can be connected to Vcc5v. This
eases the connection to “5V-only” MOSFET drivers,
such as the SC1405. The DRVs will swing to Vcc5v,
eliminating the need for +12V to +5V level shifting.
There is no Under-Voltage Lockout on V

The SC1146 is patent pending

CC2

.

9

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER

July 25, 2000

An evaluation board is available which may be ordered directly from the factory. SC1146/1405EVB is a DC/DC
converter utilizing the SC1146 four-phase controller in a high current synchronous application. The evaluation
board is intended as a guideline for board design, layout and to assess key performance parameters, such as tran­sient response, thermal stress management and input and output ripple considerations. The SC1146EVB includes
a DIP switch for mode/voltage selection as well as qualified selection of components for the SC1146 operation.
The SC1144EVB user manual contains useful general applications information applicable to SC1146 and may be
accessed from our website at www.semtech.com.

SC1146

OUTLINE DRAWING - SO-24

JEDEC MS-013AD

B17104B

ECN00-1215

The SC1146 is patent pending

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

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