LTC3417A-2

Dual Synchronous

1.5A/1A 4MHz

Step-Down DC/DC Regulator

DESCRIPTION

The LTC

®

3417A-2 is a dual constant frequency, synchro-

nous step-down DC/DC converter. Intended for medium

power applications, it operates from a 2.25V to 5.5V input

voltage range and has a constant programmable switching

frequency, allowing the use of tiny, low cost capacitors

and inductors 2mm or less in height. Each output voltage

is adjustable from 0.8V to 5V. Internal synchronous, low

R

DS(ON)

power switches provide high efﬁciency without

the need for external Schottky diodes.

A user selectable mode input allows the user to trade

off ripple voltage for light load efﬁciency. Burst Mode

operation provides high efﬁciency at light loads, while

Pulse Skip mode provides low ripple noise at light loads.

A phase mode pin allows the second channel to operate

in-phase or 180° out-of-phase with respect to channel 1.

Out-of-phase operation produces lower RMS current on

V

IN

and thus lower stress on the input capacitor.

To further maximize battery life, the P-channel MOSFETs

are turned on continuously in dropout (100% duty cycle)

and both channels draw a total quiescent current of only

100μA. In shutdown, the device draws <1μA.

L,

LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners. Protected by U.S. Patents

including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6144194.

FEATURES

n

High Efﬁciency: Up to 95%

1.5A/1A Guaranteed Minimum Output Current

Synchronizable to External Clock

No Schottky Diodes Required

Programmable Frequency Operation: 1.5MHz or

Adjustable From 0.6MHz to 4MHz

Low Ripple (<35mV

P-P

) BurstMode

®

Operation

I

Q

: 125μA in Sleep

Low R

DS(ON)

Internal Switches

Short-Circuit Protected

V

IN

: 2.25V to 5.5V

Current Mode Operation for Excellent Line and Load

Transient Response

Ultralow Shutdown Current: I

Q

< 1μA

Low Dropout Operation: 100% Duty Cycle

Power Good Ouput

Phase Pin Selects 2nd Channel Phase Relationship

with Respect to 1st Channel

Internal Soft-Start with Individual Run Pin Control

Available in Small Thermally Enhanced

(5mm × 3mm) DFN and 20-Lead TSSOP Packages

APPLICATIONS

n

GPS/Navigation Systems

Automotive Instrumentation

PC Cards

Industrial Power Supplies

General Purpose Point of Load DC/DC

TYPICAL APPLICATION

V

IN

2.5V TO 5.5V

10μF

V

OUT1

1.8V

1.5A

1.5μH

22pF

V

IN

511k

V

FB1

47μF

412k

I

TH1

5.9k

2200pF

GND

I

TH2

2.87k

6800pF

3417A-2 TA01

V

OUT2

Efﬁciency

(Burst Mode Operation)

100

REFER TO FIGURE 4

EFFICIENCY

10

95

EFFICIENCY (%)

2.2μH

V

OUT2

2.5V

1A

90

0.1

85

0.01

80

75

70

0.001

POWER LOSS

V

IN

= 3.6V

V

OUT

= 2.5V

FREQ = 1MHz

0.01

0.1

LOAD CURRENT (A)

1

3417A-2 TA01a

V

IN

FREQ

SW1

RUN1

SW2

RUN2

V

IN

866k

412k

22μF

1

POWER LOSS (W)

22pF

LTC3417A-2

V

FB2

0.001

0.0001

3417a2fa

1

LTC3417A-2

ABSOLUTE MAXIMUM RATINGS

(Note 1)

V

IN1

, V

IN2

Voltages ...................................... – 0.3V to 6V

SYNC/MODE, SW1, SW2, RUN1,

RUN2, V

FB1

, V

FB2

, PHASE, FREQ,

I

TH1

, I

TH2

Voltages......... –0.3V to ((V

IN1

or V

IN2

)+ 0.3V)

V

IN1

– V

IN2

, V

IN2

– V

IN1

.......................................... 0.3V

PGOOD Voltage ........................................... –0.3V to 6V

Operating Temperature Range (Note 2)

LTC3417AE-2 ....................................... –40°C to 85°C

LTC3417AI-2 ...................................... –40°C to 125°C

Junction Temperature (Notes 7, 8) ...................... 125°C

Storage Temperature Range................... –65°C to 150°C

PIN CONFIGURATION

TOP VIEW

RUN1

V

IN1

ITH1

V

FB1

V

FB2

I

TH2

RUN2

V

IN2

1

2

3

4

5

6

7

8

17

16 PGND1

15 SW1

14 PHASE

13 GNDA

12 FREQ

11 PGOOD

10 SW2

9

SYNC/MODE

GNDD

RUN1

V

IN1

I

TH1

V

FB1

V

FB2

I

TH2

RUN2

V

IN2

1

2

3

4

5

6

7

8

9

21

20 GNDD

19 PGND1

18 SW1

17 PHASE

16 GNDA

15 FREQ

14 PGOOD

13 SW2

12 SYNC/MODE

11 PGND2

PGND2 10

DHC PACKAGE

16-LEAD (3mm × 5mm) PLASTIC DFN

T

JMAX

= 125°C,

θ

JA

= 43°C/ W

EXPOSED PAD (PIN 17) IS PGND2/GNDD

MUST BE SOLDERED TO PCB

FE PACKAGE

20-LEAD PLASTIC TSSOP

T

JMAX

= 125°C,

θ

JA

= 38°C/ W

EXPOSED PAD (PIN 21) IS PGND2/GNDD

MUST BE SOLDERED TO PCB

ORDER INFORMATION

LEAD FREE FINISH

LTC3417AEDHC-2#PBF

LTC3417AIDHC-2#PBF

LTC3417AEFE-2#PBF

LTC3417AIFE-2#PBF

TAPE AND REEL

LTC3417AEDHC-2#TRPBF

LTC3417AIDHC-2#TRPBF

LTC3417AEFE-2#TRPBF

LTC3417AIFE-2#TRPBF

PART MARKING*

3417A2

LTC3417AFE-2

PACKAGE DESCRIPTION

16-Lead (3mm

×

5mm) Plastic DFN

16-Lead (3mm

×

5mm) Plastic DFN

20-Lead Plastic TSSOP

TEMPERATURE RANGE

–40°C to 85°C

–40°C to 125°C

–40°C to 85°C

–40°C to 125°C

Consult LTC Marketing for parts speciﬁed with wider operating temperature ranges. *The temperature grade is identiﬁed by a label on the shipping container.

Consult LTC Marketing for information on non-standard lead based ﬁnish parts.

For more information on lead free part marking, go to:

http://www.linear.com/leadfree/

For more information on tape and reel speciﬁcations, go to:

http://www.linear.com/tapeandreel/

3417a2fa

2

LTC3417A-2

The

l

denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T

A

= 25°C. V

IN

= 3.6V unless otherwise speciﬁed (Note 2).

SYMBOL

V

IN1

, V

IN2

I

FB1

, I

FB2

V

FB1

, V

FB2

ΔV

LINEREG

PARAMETER

Operating Voltage Range

Feedback Pin Input Current

Feedback Voltage

Reference Voltage Line Regulation. %/V

is the Percentage Change in V

OUT

with a

Change in V

IN

Output Voltage Load Regulation

Error Ampliﬁer Transconductance

Input DC Supply Current (Note 4)

Active Mode

CONDITIONS

V

IN1

= V

IN2

V

IN

= 6V Pin Under Test = 3V

(Note 3)

V

IN

= 2.25V to 5V (Note 3)

l

ELECTRICAL CHARACTERISTICS

MIN

2.25

0.784

TYP

MAX

5.5

± 0.1

UNITS

V

μA

V

%/V

0.8

0.02

0.816

0.2

ΔV

LOADREG

g

m(EA)

I

S

I

TH1

, I

TH2

= 0.36V (Note 3)

I

TH1

, I

TH2

= 0.84V (Note 3)

I

TH1

, I

TH2(PINLOAD)

= ±5μA (Note 3)

V

FB1

= V

FB2

= 0.75V, V

SYNC/MODE

= V

IN

,

V

RUN1

= V

RUN2

= V

IN

V

FB2

= 0.75V, V

SYNC/MODE

= V

IN

, V

RUN2

= V

IN

V

FB1

= V

FB2

= 1V, V

SYNC/MODE

= V

IN

, V

RUN1

=

V

RUN2

= V

IN

V

RUN1

= V

RUN2

= 0V

V

FREQ

= V

IN

V

FREQ

: R

T

= 143k

V

FREQ

: Resistor (Note 6)

1.2

0.85

2.1

1.4

V

IN1

= 3.6V (Note 5)

V

IN1

= 3.6V (Note 5)

V

IN2

= 3.6V (Note 5)

V

IN2

= 3.6V (Note 5)

V

IN1

= 6V, V

ITH1

= 0V, V

RUN1

= 0V

V

IN2

= 6V, V

ITH2

= 0V, V

RUN2

= 0V

V

IN1

, V

IN2

Ramping Down

V

IN1

, V

IN2

Ramping Up

V

FB1

or V

FB2

Ramping Up

V

FB1

or V

FB2

Ramping Down

1.9

1.95

0.02

–0.02

1400

400

260

125

0.01

1.5

1

2.5

1.7

0.088

0.084

0.16

0.15

0.01

2.07

2.12

–6

120

0.3

V

IN

–0.5

0.85

0.2

–0.2

%

μS

600

400

250

1

1.8

1.25

4

μA

MHz

A

Ω

I

S

Half Active Mode (V

RUN2

= 0V, 1.5A Only) V

FB1

= 0.75V, V

SYNC/MODE

= V

IN

, V

RUN1

= V

IN

Half Active Mode (V

RUN1

= 0V, 1A Only)

Both Channels in Sleep Mode

Shutdown

f

OSC

Oscillator Frequency

I

LIM1

I

LIM2

R

DS(ON)1

R

DS(ON)2

I

SW1(LKG)

I

SW2(LKG)

V

UVLO

T

PGOOD

Peak Switch Current Limit on SW1 (1.5A)

Peak Switch Current Limit on SW2 (1A)

SW1 Top Switch On-Resistance (1.5A)

SW1 Bottom Switch On-Resistance

SW2 Top Switch On-Resistance (1A)

SW2 Bottom Switch On-Resistance

Switch Leakage Current SW1 (1.5A)

Switch Leakage Current SW2 (1A)

Undervoltage Lockout Threshold

Threshold for Power Good. Percentage

Deviation from V

FB

Steady State

(Typically 0.8V)

Power Good Pull-Down On-Resistance

RUN1, RUN2 Threshold

PHASE Threshold High-CMOS Levels

PHASE Threshold Low-CMOS Levels

V

IN

= 6V, Pin Under Test = 3V

1

2.2

2.25

μA

V

%

R

PGOOD

V

RUN1,

V

RUN2

V

PHASE

300

1.5

Ω

V

0.5

±0.01

±1

0.5

V

IN

–0.5

V

IN

–0.5

V

μA

V

I

RUN1,

I

RUN2,

I

PHASE,

RUN1, RUN2, PHASE and SYNC/MODE

Leakage Current

I

SYNC/MODE

VTL

SYNC/MODE

VTH

SYNC/MODE

VTH

FREQ

SYNC/MODE Threshold Voltage Low

SYNC/MODE Threshold Voltage High

FREQ Threshold Voltage High

3417a2fa

3

LTC3417A-2

ELECTRICAL CHARACTERISTICS

Note 1:

Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2:

The LTC3417AE-2 is guaranteed to meet speciﬁed performance

from 0°C to 85°C. Speciﬁcations over the –40°C to 85°C operating

ambient temperature range are assured by design, characterization

and correlation with statistical process controls. The LTC3417AI-2 is

guaranteed to meet performance speciﬁcations over the –40°C to 125°C

operating temperature range.

Note 3:

The LTC3417A-2 is tested in feedback loop which servos V

FB1

to

the midpoint for the error ampliﬁer (V

ITH1

= 0.6V) and V

FB2

to the midpoint

for the error ampliﬁer (V

ITH2

= 0.6V).

Note 4:

Total supply current is higher due to the internal gate charge being

delivered at the switching frequency.

Note 5:

Switch on-resistance is guaranteed by design and test correlation

on the DHC package and by ﬁnal test correlation on the FE package.

Note 6:

Variable frequency operation with resistor is guaranteed by design

but not production tested and is subject to duty cycle limitations.

Note 7:

This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 125°C when overtemperature protection is active.

Continuous operation above the speciﬁed maximum operating junction

temperature may impair device reliability.

Note 8:

T

J

is calculated from the ambient temperature, T

A

, and power

dissipation, P

D

, according to the following formula:

LTC3417AEDHC-2: T

J

= T

A

+ (P

D

• 43°C/W)

LTC3417AEFE-2: T

J

= T

A

+ (P

D

• 38°C/W)

TYPICAL PERFORMANCE CHARACTERISTICS

OUT1 Burst Mode Operation

OUT1 Pulse Skipping

Mode Operation

OUT1 Forced Continuous

Mode Operation

V

OUT

20mV/DIV

V

OUT

20mV/DIV

V

OUT

20mV/DIV

I

L

250mA/DIV

I

L

250mA/DIV

I

L

250mA/DIV

2μs/DIV

V

IN

= 3.6V

V

OUT

= 1.8V

I

LOAD

= 100mA

REFER TO FIGURE 4

3417A-2 G01

V

IN

= 3.6V

2μs/DIV

V

OUT

= 1.8V

I

LOAD

= 100mA

REFER TO FIGURE 4

3417A-2 G02

V

IN

= 3.6V

2μs/DIV

V

OUT

= 1.8V

I

LOAD

= 100mA

REFER TO FIGURE 4

3417A-2 G03

OUT2 Burst Mode Operation

OUT2 Pulse Skipping

Mode Operation

OUT2 Forced Continuous

Mode Operation

V

OUT

20mV/DIV

V

OUT

20mV/DIV

V

OUT

20mV/DIV

I

L

250mA/DIV

I

L

250mA/DIV

I

L

250mA/DIV

V

IN

= 3.6V

2μs/DIV

V

OUT

= 2.5V

I

LOAD

= 60mA

REFER TO FIGURE 4

3417A-2 G04

V

IN

= 3.6V

2μs/DIV

V

OUT

= 2.5V

I

LOAD

= 60mA

REFER TO FIGURE 4

3417A-2 G05

V

IN

= 3.6V

2μs/DIV

V

OUT

= 2.5V

I

LOAD

= 60mA

REFER TO FIGURE 4

3417A-2 G06

3417a2fa

4

LTC3417A-2

TYPICAL PERFORMANCE CHARACTERISTICS

OUT1 Efﬁciency vs Load Current

100

V

IN

= 2.5V

V

OUT

= 1.8V

95

90

EFFICIENCY (%)

85

80

75

70

65

60

0.001

0.01

0.1

Burst Mode

OPERATION

PULSE SKIP

FORCED

CONTINUOUS

REFER TO FIGURE 4

1

10

3417A-2 G07

OUT2 Efﬁciency vs Load Current

100

V

IN

= 3.6V

V

OUT

= 2.5V

95

90

85

80

75

70

65

60

0.001

0.01

0.1

Burst Mode

OPERATION

PULSE SKIP

FORCED

CONTINUOUS

REFER TO FIGURE 4

1

LOAD CURRENT (A)

3417A-2 G08

OUT1 Efﬁciency vs V

IN

(Burst Mode Operation)

100

95

EFFICIENCY (%)

90

I

LOAD

= 1.4A

85

80

75

70

2

2.5

3

3.5

REFER TO FIGURE 4

4

4.5

5

5.5

V

IN

(V)

3417A-2 G09

V

OUT

= 1.8V

I

LOAD

= 460mA

LOAD CURRENT (A)

OUT2 Efﬁciency vs V

IN

(Pulse Skipping Mode)

100

I

LOAD

= 250mA

95

EFFICIENCY (%)

90

85

80

75

70

2

2.5

3

3.5

V

OUT

= 2.5V

REFER TO FIGURE 4

4

4.5

5

5.5

I

LOAD

= 800mA

V

OUT1

100mV/DIV

Load Step OUT1

Load Step OUT2

V

OUT2

100mV/DIV

I

OUT1

500mA/DIV

I

OUT2

500mA/DIV

V

IN

= 3.6V

100μs/DIV

V

OUT

= 1.8V

I

LOAD

= 0.25A to 1.4A

REFER TO FIGURE 4

3417A-2 G11

V

IN

= 3.6V

100μs/DIV

V

OUT

= 2.5V

I

LOAD

= 0.25A to 0.8A

REFER TO FIGURE 4

3417A-2 G12

V

IN

(V)

3417A-2 G10

Efﬁciency vs Frequency OUT1

94

92

EFFICIENCY (%)

90

88

86

84

82

0

1

2

3

4

5

FREQUENCY (MHz)

3417A-2 G13

Efﬁciency vs Frequency OUT2

90

85

EFFICIENCY (%)

80

75

70

65

60

0

1

2

FREQUENCY (MHz)

3417A-2 G14

R

DS(ON)

vs V

IN

OUT1

0.105

T

A =

27°C

T

A

= 27°C

V

IN

= 3.6V

V

OUT

= 1.8V

I

OUT

= 300mA

0.100

P-CHANNEL SWITCH

R

DS(ON)

(Ω)

T

A

= 27°C

V

IN

= 3.6V

V

OUT

= 2.5V

I

OUT

= 100mA

3

4

0.095

0.090

0.085

N-CHANNEL SWITCH

0.080

2

2.5

3

3.5

4

4.5

5

5.5

V

IN

(V)

3417A-2 G15

3417a2fa

5

参数名称	属性值
是否Rohs认证	符合
包装说明	HVSON, SOLCC16,.12,20
Reach Compliance Code	compliant
模拟集成电路 - 其他类型	DUAL SWITCHING CONTROLLER
控制模式	CURRENT-MODE
最大输入电压	5.5 V
最小输入电压	2.25 V
标称输入电压	3.6 V
JESD-30 代码	R-PDSO-N16
长度	5 mm
功能数量	1
端子数量	16
最高工作温度	85 °C
最低工作温度	-40 °C
最大输出电压	5 V
最小输出电压	0.8 V
封装主体材料	PLASTIC/EPOXY
封装代码	HVSON
封装等效代码	SOLCC16,.12,20
封装形状	RECTANGULAR
封装形式	SMALL OUTLINE, HEAT SINK/SLUG, VERY THIN PROFILE
座面最大高度	0.8 mm
最大供电电流 (Isup)	0.6 mA
表面贴装	YES
切换器配置	BUCK
最大切换频率	4000 kHz
技术	CMOS
温度等级	INDUSTRIAL
端子形式	NO LEAD
端子节距	0.5 mm
端子位置	DUAL
宽度	3 mm
Base Number Matches	1

	LTC3417AEDHC#TRMPBF
描述	Dual Switching Controller
是否Rohs认证	符合
包装说明	HVSON, SOLCC16,.12,20
Reach Compliance Code	compliant
模拟集成电路 - 其他类型	DUAL SWITCHING CONTROLLER
控制模式	CURRENT-MODE
最大输入电压	5.5 V
最小输入电压	2.25 V
标称输入电压	3.6 V
JESD-30 代码	R-PDSO-N16
长度	5 mm
功能数量	1
端子数量	16
最高工作温度	85 °C
最低工作温度	-40 °C
最大输出电压	5 V
最小输出电压	0.8 V
封装主体材料	PLASTIC/EPOXY
封装代码	HVSON
封装等效代码	SOLCC16,.12,20
封装形状	RECTANGULAR
封装形式	SMALL OUTLINE, HEAT SINK/SLUG, VERY THIN PROFILE
座面最大高度	0.8 mm
最大供电电流 (Isup)	0.6 mA
表面贴装	YES
切换器配置	BUCK
最大切换频率	4000 kHz
技术	CMOS
温度等级	INDUSTRIAL
端子形式	NO LEAD
端子节距	0.5 mm
端子位置	DUAL
宽度	3 mm
Base Number Matches	1

LTC3417AEDHC#TRMPBF

LTC3417AEDHC#TRMPBF概述

LTC3417AEDHC#TRMPBF规格参数

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