SC1566I5M-1.8T [SEMTECH]

Adjustable Positive LDO Regulator, 1.764V Min, 1.836V Max, 0.6V Dropout, PSSO5, TO-263, 5 PIN;


型号：	SC1566I5M-1.8T
厂家：	SEMTECH CORPORATION
描述：	Adjustable Positive LDO Regulator, 1.764V Min, 1.836V Max, 0.6V Dropout, PSSO5, TO-263, 5 PIN
文件：	总9页 (文件大小：127K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com

DESCRIPTION

FEATURES

•

350mV dropout @ 3A

The SC1566 is a high performance positive voltage

regulator designed for use in applications requiring

very low dropout voltage at up to 3 Amps. Since it has

superior dropout characteristics compared to regular

LDOs, it can be used to supply 2.5V on motherboards

or 2.8V on peripheral cards from the 3.3V supply thus

allowing heat sink size reduction or elimination.

Additionally, the five pin versions of SC1566 have an

enable pin, to further reduce power dissipation while

shut down. The SC1566 provides excellent regulation

over variations in line, load and temperature.

Adjustable output from 1.200V to 4.8V

2.5V and 1.8V options (5 pin parts also adjustable

externally using resistors)

•

Over current and over temperature protection

Enable pin

10µA quiescent current in shutdown

Low reverse leakage (output to input)

Surface mount and through-hole packages

Full industrial temperature range

APPLICATIONS

The SC1566 is available as three terminal fixed output

voltage and five terminal fixed or adjustable output

voltage devices with enable. Two package options are

available: TO-263 and TO-220.

•

Battery powered systems

Motherboards

Peripheral cards

PCMCIA cards

ORDERING INFORMATION

ABSOLUTE MAXIMUM RATINGS

DEVICE

SC1566IM-X.X

SC1566I5M-X.X

SC1566IT-X.X

SC1566I5T-X.X

PACKAGE

TO-263-3L⁽³⁾

TO-263-5L⁽³⁾See Notes 1, 2

V_OUT(V)

Parameter

Symbol

V_IN

Max

Units

See Note 1

Input Voltage

5.5

TO-220-3L

TO-220-5L

See Note 1

Power

Dissipation

P_D

Internally

Limited

See Notes 1, 2

Notes:

Thermal Resistance

Junction to Case

SC1566CM TO-263

SC1566CT TO-220

(1) Where -X.X denotes voltage options. Available

voltages are: 2.5V and 1.8V.

(2) Output voltage can be adjusted using external re-

sistors, see Pin Description.

3.0

°C/W

θ_JC

Thermal Resistance

Junction to Ambient

SC1566CM TO-263

SC1566CT TO-220

(3) Add suffix ‘TR’ for tape and reel.

°C/W

°C

θ_JA

BLOCK DIAGRAM

T_A

Operating Ambient

Temperature Range

-40 to+85

Operating Junction

Temperature Range

T_J

-40 to 150

°C

Storage Temperature

Range

T_STG

-65 to 150

260

°C

Lead Temperature

(Soldering) 10 Sec.

T_LEAD

ESD Rating

ESD

* 5-Lead Version Only

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

PIN CONFIGURATIONS

TO-263-5

TO-263-3

SC1566 5-PIN VERSIONS

SC1566 3-PIN VERSIONS⁽¹⁾

FUNCTION

VIN

FUNCTION

VIN

TO-220-3

TO-220-5

GND

ADJ

TAB IS GROUND

NOTE:

(1) 3-pin versions are fixed output voltage only.

PIN DESCRIPTIONS

ADJ

This pin, when grounded, sets the output voltage to that set by the internal feedback resistors. If ex-

ternal feedback resistors are used, the output voltage will be: (See Application Circuit)

1.200 (R1 + R2)

Volts

Enable Input. Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to a

fraction of its operating value. The device will be enabled if this pin is left open. Connect to VIN if not

being used.

GND

VIN

Reference ground.

Input voltage. For regulation at full load, the input to this pin must be between (VO + 0.7V) to 5.5V.

Minimum VIN = 2.2V.

This pin is the power output of this device.

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

ELECTRICAL CHARACTERISTICS

Unless specified: V_EN= V_IN

Adjustable Option: V_IN= 2.2 to 5.5V and I_O= 10mA to 3.0A

Fixed Options: V_IN= (V_O+ 0.7V) to 5.5V and I_O= 0mA to 3.0A

Values in bold apply over the full operating temperature range.

Parameter

Symbol

Test Conditions

Min

Typ

V_O

Max

Units

Output Voltage⁽¹⁾

(Internal Fixed Voltage)

Reference Voltage⁽¹⁾

(5-Pin Versions)

Line Regulation⁽¹⁾

V_O

V_IN= V_O+ 0.7V, I_O= 10mA

0.99V_O

0.98V_O

1.188

1.176

1.01V_O

1.02V_O

1.212

1.224

0.3

V_O

V_REF

V_IN= 2.2V, I_O= 10mA

1.200

REG_(LINE)

V_IN= (V_O+ 0.25V) to 5.5V,

I_OUT= 10mA

0.035

Load Regulation⁽¹⁾

Dropout Voltage⁽²⁾

REG_(LOAD)

V_D

V_IN= V_O+ 0.7V

I_LOAD= 10mA

0.2

0.4

_LOAD= 500mA

100

150

300

400

450

600

1.75

I_LOAD= 1.5A

200

350

I_LOAD= 3A

Quiescent Current

I_Q

V_IN= 3.3V

0.75

µA

V_IN= 5.5V, V_EN= 0V

V_ADJ= V_REF

Adjust Pin Current⁽³⁾

Adjust Pin Threshold⁽⁴⁾

Enable Pin Current

Enable Pin Threshold

I_ADJ

V_TH(ADJ)

I_EN

0.20

1.5

0.40

0.10

2.0

V_EN= 0V

µA

V_IH

V_IL

I_O

V_IN= 3.3V

0.4

Minimum Load Current⁽⁵⁾

Current Limit

V_IN= V_O+ 0.7V

µA

I_CL

4.5

3.0

6.5

NOTES:

(1) Low duty cycle pulse testing with Kelvin connections required.

(2) Defined as the input to output differential at which the output voltage drops to 1% below the value measured at

a differential of 0.7V.

(3) Guaranteed by design.

(4) When V_ADJexceeds this threshold, the “Sense Select” switch disconnects the internal feedback chain from the

error amplifier and connects V_ADJinstead.

(5) Required to maintain regulation. Voltage set resistors R1 and R2 are usually utilized to meet this requirement.

Adjustable versions only.

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

TYPICAL APPLICATION - 5 PIN VERSION (Externally Set Output Voltage)⁽¹⁾⁽²⁾

SC1566

VIN

ENABLE

ADJ

GND

1.200 (R1 + R2)

Volts

TYPICAL APPLICATION - 5 PIN VERSION (Internally Set Output Voltage)⁽²⁾

SC1566

VIN

ENABLE

GND

TYPICAL APPLICATION - 3 PIN VERSION⁽²⁾

SC1566

VIN

VIN VO

GND

Notes:

(1) Maximum VO setpoint for 1.8V parts = 5.4V.

(2) This device is designed to operate with ceramic input and output capacitors.

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

TYPICAL CHARACTERISTICS

Dropout Voltage vs. Output Current

vs. Junction Temperature

Dropout Voltage vs. Junction

Temperature vs. Output Current

500

450

400

350

300

250

200

150

100

500

450

400

350

300

250

200

150

100

150°C

I_O= 3A

25°C

0°C

-40°C

I_O= 1.5A

I_O= 0.5A

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

150

-50

-25

100

125

150

I_O(A)

T_J(°C)

Output Voltage (2.5V) vs. Junction

Temperature vs. Output Current

Output Voltage (2.5V) vs. Junction

Temperature vs. Output Current

2.550

2.540

2.530

2.520

2.510

2.500

2.490

2.480

2.470

2.460

2.450

2.550

2.540

2.530

2.520

2.510

2.500

2.490

2.480

2.470

2.460

2.450

VIN = 3.2V

VIN = 5.5V

I_O= 10mA

I_O= 3A

I_O= 10mA

I_O= 3A

-50

-25

100

125

-50

-25

100

125

150

_J(°C)

Reference Voltage vs. Junction

Temperature vs. Output Current

Reference Voltage vs. Junction

Temperature vs. Output Current

1.225

1.220

1.215

1.210

1.205

1.200

1.195

1.190

1.185

1.180

1.175

1.225

1.220

1.215

1.210

1.205

1.200

1.195

1.190

1.185

1.180

1.175

VIN = 2.2V

VIN = 5.5V

_O= 10mA

I_O= 3A

I_O= 10mA

-50

-25

100

125

-50

-25

100

125

150

_J(°C)

T_J(°C)

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

TYPICAL CHARACTERISTICS (Cont.)

Quiescent Current vs.

Junction Temperature

Off-State Quiescent Current vs.

Junction Temperature

700

VIN = 5.5V

VIN = 3.3V

690

680

670

660

650

640

630

620

610

600

-50

-25

100

125

150

-50

-25

100

125

150

T_J(°C)

Thermal Considerations

APPLICATIONS INFORMATION

The power dissipation in the SC1566 is approximately

equal to the product of the output current and the input

to output voltage differential:

Introduction

The SC1566 is intended for applications such as

P_D

≈

(

VIN − VOUT

• I_O

)

graphics cards where high current capability and very

low dropout voltage are required. It provides a very

simple, low cost solution that uses little pcb real estate

and typically does not require a heatsink. Additional

features include an enable pin to allow for a very low

power consumption standby mode, and a fully ad-

justable output (5-pin versions).

The absolute worst-case dissipation is given by:

P_{D(MAX )}

(VIN _{(MAX )}− VOUT

)

• I_{O(MAX )}+ VIN _{(MAX )}• I_{Q(MAX )}

(MIN )

For a typical scenario, VIN = 3.3V ± 5%, VOUT = 2.8V

and I_O= 2.5A, therefore:

Component Selection

VIN_(MAX)= 3.465V, VOUT_(MIN)= 2.744V and

I_Q(MAX)= 1.75mA,

Input capacitor - a 4.7µF or 10µF ceramic capacitor is

recommended. This allows for the device being some

distance from any bulk capacitance on the rail. Addi-

tionally, input droop due to load transients is reduced,

improving load transient response. Additional capaci-

tance may be added if required by the application.

Thus P_D(MAX)= 1.81W.

Using this figure, and assuming T_A(MAX)= 85°C, we can

calculate the maximum thermal impedance allowable

to maintain T_J≤ 150°C:

Output capacitor - a minimum bulk capacitance of

22µF, along with a 0.1µF ceramic decoupling capacitor

is recommended. Increasing the bulk capacitance will

improve the overall transient response. The use of

multiple lower value ceramic capacitors in parallel to

achieve the desired bulk capacitance will not cause

stability issues. Although designed for use with ce-

ramic output capacitors, the SC1566 is extremely toler-

ant of output capacitor ESR values and thus will also

work comfortably with tantalum output capacitors.

(

T_{J(MAX )}− T_{A(MAX )}

)

(

150 − 85

)

= 36°C/ W

R_TH(J

A)(MAX )

−

P_{D(MAX )}

1.81

= 3°C/ W and R_TH(C= 0°C/ W,

C)(MAX )

−

therefore R_TH(S

= 33°C/ W

A)(MAX )

−

This should be achievable using pcb copper area to aid

in conducting the heat away from the device, such as a

large (~2 squ. inch) pad connected to the tab of the

device. Internal ground/power planes and air flow will

also assist in removing heat. For higher power dissipa-

tions it may be necessary to use a small heatsink and

the TO-220 package.

External voltage selection resistors (5-pin parts) - the

use of 1% resistors, and designing for a current flow

≥ 10µA is recommended to ensure a well regulated

output (thus R2 ≤ 120kΩ).

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

DEVICE OUTLINE - TO-263-3L

MINIMUM LAND PATTERN - TO-263-3L⁽¹⁾

Note:

(1) Additional copper should be used to lower θ_JAas required.

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

DEVICE OUTLINE - TO-263-5L

MINIMUM LAND PATTERN - TO-263-5L⁽¹⁾

Note:

(1) Additional copper should be used to lower θ_JAas required.

652 MITCHELL ROAD NEWBURY PARK CA 91320

VERY LOW DROPOUT 3 AMP

REGULATOR WITH ENABLE

SC1566

July 28, 1999

DEVICE OUTLINE - TO-220-3L

DEVICE OUTLINE - TO-220-5L

652 MITCHELL ROAD NEWBURY PARK CA 91320

SC1566I5M-1.8T [SEMTECH]

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