SC2446 datasheet(1/38 Pages) SEMTECH

номер детали	SC2446

подробное описание детали	Dual-Phase Single or Two Output Synchronous Step-Down Controllers

PDF	38 Pages

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производитель	SEMTECH [Semtech Corporation]

домашняя страница	http://www.semtech.com

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POWER MANAGEMENT

1

U.S. Patent No. 6,441,597, www.semtech.com

SC2446

Dual-Phase Single or Two Output

Synchronous Step-Down Controllers

Description

Revision: September 9, 2004

Features

Typical Application Circuit

R76

C102

RCS-

R78

VO1

C99

RFILTER

VIN

RCS+

SYNC

C101

R81

C106

C97

RCS-

C105

C92

U1

SC2446

REFOUT

PGND

GDH2

BST2

IN1-

VPN1

SYNC

CS1+

PVCC

COMP1

SS1/EN1

CS1-

SS2/EN2

COMP2

IN2-

REFIN

CS2-

CS2+

VPN2

VIN2

BST1

GDH1

GDL1

GDL2

REF

Rosc

AGND

AVCC

R80

D11

R77

RFILTER

C96

C103

R73

C100

CFILTER

C93

+

C95

R85

C104

R83

C109

R82

CFILTER

VIN

REF

Dual Independant Outputs

C94

R84

Q22

D12

R74

VIN

R75

L12

C108

Q23

C107

R79

Q21

+

C98

Q24

RCS+

VO2

L11

The SC2446 is a high-frequency dual synchronous step-

down switching power supply controller. It provides out-

of-phase high-current output gate drives to all N-chan-

nel MOSFET power stages. The SC2446 operates in syn-

chronous continuous-conduction mode. Both phases are

capable of maintaining regulation with sourcing or sink-

ing load currents, making the SC2446 suitable for gen-

erating both V

DDQ and the tracking VTT for DDR applica-

tions.

The SC2446 employs fixed frequency peak current-mode

control for the ease of frequency compensation and fast

transient response.

The dual-phase step-down controllers of the SC2446 can

be configured to provide two individually controlled and

regulated outputs or a single output with shared current

in each phase. The Step-down controllers operate from an

input of at least 4.7V and are capable of regulating out-

puts as low as 0.5V

The step-down controllers in the SC2446 have the pro-

vision to sense a synthesized MOSFET R

DS(ON) for

cur-

rent-mode control. This sensing scheme (U.S. patent

6,441,597) eliminates the need of the current-sense re-

sistor and is more noise-immune than direct sensing of

the high-side or the low-side MOSFET voltage. Precise cur-

rent-sensing with sense resistor is optional.

Individual soft-start and overload shutdown timer is in-

cluded in each step-down controller. The SC2446 imple-

ments hiccup overload protection. In two-phase single-

output configuration, the master timer controls the soft-

start and overload shutdown functions of both control-

lers.

2-Phase synchronous continuous conduction mode

for high efficiency step-down converters

Out of phase operation for low input current ripples

Output source and sink currents

Fixed frequency peak current-mode control

75mV/-110mV maximum current sense voltage

Synthesized MOSFET R

DS(ON) current-sensing for

low-cost applications

Optional resistor current-sensing for precise current-

limit

Dual outputs or 2-phase single output operation

Excellent current sharing between individual phases

Wide input voltage range: 4.7V to 16V

Individual soft-start, overload shutdown and enable

Duty cycle up to 88%

0.5V feedback voltage for low-voltage outputs

External reference input for DDR applications

Buffered V

DDQ/2 output

Programmable frequency up to 1 MHz per phase

External synchronization

Industrial temperature range

28-lead TSSOP - EDP package

Applications

Telecommunication power supplies

DDR memory power supplies

Graphic power supplies

Servers and base stations

Figure 1

Аналогичный номер детали - SC2446

производитель	номер детали	датащи	подробное описание детали
Semtech Corporation	SC2446A	525Kb / 27P	Dual-Phase, Single or Dual Output Synchronous Step-Down Controller
	SC2446AEVB	525Kb / 27P	Dual-Phase, Single or Dual Output Synchronous Step-Down Controller
	SC2446AITSTRT	525Kb / 27P	Dual-Phase, Single or Dual Output Synchronous Step-Down Controller

More results

Аналогичное описание - SC2446

производитель	номер детали	датащи	подробное описание детали
Semtech Corporation	SC2446A	525Kb / 27P	Dual-Phase, Single or Dual Output Synchronous Step-Down Controller
	SC2447	755Kb / 26P	Dual-Phase, Single or Dual Output Synchronous Step-Down Controller
	SC2443	1Mb / 20P	Dual-Phase Single or Two Output Synchronous Step-Down Controller
	SC2443	1Mb / 22P	Dual-Phase Single or Two Output Synchronous Step-Down Controller
Linear Technology	LTC3869	2Mb / 40P	Dual, 2-Phase Synchronous Step-Down DC/DC Controllers
Texas Instruments	TPS40322	1,023Kb / 40P	Dual Output or Two-Phase Synchronous Buck Controller
Linear Technology	LTC3869	524Kb / 42P	Dual, 2-Phase Synchronous Step-Down DC/DC Controllers
Linear Technology	LTC3869-2	524Kb / 42P	Dual, 2-Phase Synchronous Step-Down DC/DC Controllers
Texas Instruments	TPS40322	1Mb / 47P	Dual Output or Two-Phase Synchronous Buck Controller
Linear Technology	LTC3869EUFD	313Kb / 8P	Dual, 2-Phase Synchronous Step-Down DC/DC Controllers

More results

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Аналогичный номер детали - SC2446

Аналогичное описание - SC2446

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