Semiconductor NCP1529 Service Manual

Buck Converter - DC-DC,
High Efficiency, Adjustable
Output Voltage, Low Ripple

1.7 MHz, 1 A

NCP1529

The NCP1529 step−down DC−DC converter is a monolithic
integrated circuit for portable applications powered from one cell
Li−ion or three cell Alkaline/NiCd/NiMH batteries. The device is able
to deliver up to 1.0 A on an output voltage range externally adjustable
from 0.9 V to 3.9 V or fixed at 1.2 V or 1.35 V. It uses synchronous
rectification to increase efficiency and reduce external part count. The
device also has a built−in 1.7 MHz (nominal) oscillator which reduces
component size by allowing a small inductor and capacitors. Automatic
switching PWM/PFM mode offers improved system efficiency.

Additional features include integrated soft−start, cycle−by−cycle
current limiting and thermal shutdown protection.

The NCP1529 is available in a space saving, low profile
2x2x0.5 mm UDFN6 package and TSOP−5 package.

Features

• Up to 96% Efficiency

• Best In Class Ripple, including PFM mode

• Source up 1.0 A

• 1.7 MHz Switching Frequency

• Adjustable from 0.9 V to 3.9 V or Fixed at 1.2 V or 1.35 V

• Synchronous rectification for higher efficiency

• 2.7 V to 5.5 V Input Voltage Range

• Low Quiescent Current 28 mA

• Shutdown Current Consumption of 0.3 mA

• Thermal Limit Protection

• Short Circuit Protection

• All Pins are Fully ESD Protected

• These are Pb−Free Devices

Typical Applications

• Cellular Phones, Smart Phones and PDAs

• Digital Still Cameras

• MP3 Players and Portable Audio Systems

• Wireless and DSL Modems

• USB Powered Devices

• Portable Equipment

V

IN

OFF ON

VINENSW

C

IN

FB

GND

L

C

OUT

R1

R2

V

OUT

C

ff

OFF ON

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MARKING
DIAGRAM

5

TSOP−5

5

1

DXJ = Specific Device Code
A = Assembly Location
Y = Year
W = Work Week
G = Pb−Free Package
(Note: Microdot may be in either location)

XX = Specific Device Code
M = Date Code
G = Pb−Free Package
(Note: Microdot may be in either location)

ORDERING INFORMATION

See detailed ordering and shipping information in the package
dimensions section on page 14 of this data sheet.

V

IN

C

IN

SN SUFFIX

CASE 483

UDFN6

MU SUFFIX

CASE 517AB

VINENSW

FB

GND

1

1
2
3

L

DXJAYWG

G

XXMG

G

V

OUT

C

OUT

6
5
4

Figure 1. Typical Application for Adjustable Version

© Semiconductor Components Industries, LLC, 2010

August, 2020− Rev. 6

Figure 2. Typical Application for Fixed Version

1 Publication Order Number:

NCP1529/D

NCP1529

PIN FUNCTION DESCRIPTION

Pin

TSOP−5

1 6 EN Analog Input Enable for switching regulators. This pin is active HIGH and is turned off by

2 2,4,7

3 5 SW Analog Output Connection from power MOSFETs to the Inductor.

4 3 VIN Analog /

5 1 FB Analog Input Feedback voltage from the output of the power supply. This is the input to the

1. Exposed pad for UDFN6 package, named Pin 7, must be connected to system ground.

Pin

UDFN6

(Note 1)

Pin Name Type Description

logic LOW on this pin.

GND Analog /

Power Ground

Power Input

This pin is the GND reference for the NFET power stage and the analog
section of the IC. The pin must be connected to the system ground.

Power supply input for the PFET power stage, analog and digital blocks. The
pin must be decoupled to ground by a 4.7 mF ceramic capacitor.

error amplifier.

PIN CONNECTIONS

EN

GND

SW

1

2

3

(Top View)

FB

5

4

VIN

FB

GND

VIN

1

2

3

(Top View)

7

EN

6

5

SW

4

GND

Figure 3. Pin Connections − TSOP−5 Figure 4. Pin Connections − UDFN6

PERFORMANCES

100

90

80

70

60

50

40

30

EFFICIENCY (%)

20

10

0

0 500 1000

I

(mA)

OUT

Figure 5. Efficiency vs Output Current

V

= 3.6 V, V

IN

OUT

= 3.3 V

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NCP1529

FUNCTIONAL BLOCK DIAGRAM

Q1

V

4.7 mF

Enable

battery

VIN

GND

EN

LOGIC

CONTROL

& THERMAL

SHUTDOWN

Q2

PWM/PFM
CONTROL

I

LIMIT

REFERENCE

VOLTAGE

Figure 6. Simplified Block Diagram

SW

FB

2.2 mH

10 mF

R1

R2

18 pF

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NCP1529

MAXIMUM RATINGS

Rating Symbol Value Unit

Minimum Voltage All Pins V

Maximum Voltage All Pins (Note 2) V

Maximum Voltage EN V

Thermal Resistance, Junction−to−Air (TSOP−5 Package)
Thermal Resistance using TSOP−5 Recommended Board Layout (Note 9)

Thermal Resistance, Junction−to−Air (UDFN6 Package)
Thermal Resistance using UDFN6 Recommended Board Layout (Note 9)

Operating Ambient Temperature Range (Notes 7 and 8) T

Storage Temperature Range T

Junction Operating Temperature (Notes 7 and 8) T

min

max

max

R

q

JA

R

q

JA

A

stg

j

Latchup Current Maximum Rating (TA = 85°C) (Note 5) Other Pins Lu $100 mA

ESD Withstand Voltage (Note 4)
Human Body Model

V

esd

Machine Model

Moisture Sensitivity Level (Note 6) MSL 1 per IPC

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.

2. Maximum electrical ratings are defined as those values beyond which damage to the device may occur at T

3. According to JEDEC standard JESD22−A108B.

4. This device series contains ESD protection and exceeds the following tests:

Human Body Model (HBM) per JEDEC standard: JESD22−A114.
Machine Model (MM) per JEDEC standard: JESD22−A115.

5. Latchup current maximum rating per JEDEC standard: JESD78.

6. JEDEC Standard: J−STD−020A.

7. In applications with high power dissipation (low V

considerations − thermal dissipation vias, traces or planes and PCB material − can significantly improve junction to air thermal resistance

(for more information, see design and layout consideration section). Environmental conditions such as ambient temperature TA brings

R

q

JA

thermal limitation on maximum power dissipation allowed.

, high I

IN

), special care must be paid to thermal dissipation issues. Board design

OUT

The following formula gives calculation of maximum ambient temperature allowed by the application:

= TJ

T

A MAX

Where: T

8. To prevent permanent thermal damages, this device include a thermal shutdown which engages at 180°C (typ).

− (R

x Pd)

MAX

is the junction temperature,

J

is the maximum power dissipated by the device (worst case of the application),

P

d

and R

q

JA

is the junction−to−ambient thermal resistance.

q

JA

9. Board recommended TSOP−5 and UDFN6 layouts are described on Layout Considerations section.

−0.3 V

7.0 V

VIN + 0.3 V

300

°C/W

110

220

°C/W

40

−40 to 85 °C

−55 to 150 °C

−40 to 150 °C

2.0

kV

200

= 25°C.

A

V

1200

1000

800

UDFN6

TSOP−5

600

400

, POWER DISSIPATION (mW)

200

D

P

0

−40 −200 20 406080

TA, AMBIENT TEMPERATURE (°C)

Figure 8. Power Derating

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1200

UDFN6

1000

800

TSOP−5

600

RENT (mA)

400

, MAXIMUM OUTPUT CUR-

200

OUTmax

I

0

2.7 3.2 3.7 4.2 4.7 5.2
, INPUT VOLTAGE (V)

V

IN

Figure 7. Maximum Output Current, TA = 455C

4

NCP1529

ELECTRICAL CHARACTERISTICS (Typical values are referenced to T

+85°C ambient temperature, unless otherwise noted, operating conditions V

= +25°C, Min and Max values are referenced −40°C to

A

= 3.6 V, V

IN

= 1.2 V, unless otherwise noted.)

OUT

Rating Conditions Symbol Min Typ Max Unit

INPUT VOLTAGE

Input Voltage Range

Quiescent Current No Switching, No load I

Standby Current EN Low I

Under Voltage Lockout VIN Falling V

Under Voltage Hysteretis V

V

in

Q

STB

UVLO

UVLOH

2.7 − 5.5 V

− 28 39

− 0.3 1.0

mA

mA

2.2 2.4 2.55 V

− 100 − mV

ANALOG AND DIGITAL PIN

Positive going Input High Voltage Threshold

Negative going Input High Voltage Threshold V

EN Threshold Hysteresis V

EN High Input Current EN = 3.6 V I

V

IH

ENH

ENH

1.2 − − V

− − 0.4 V

IL

− 100 − mV

− 1.5 −

mA

OUTPUT

Feedback Voltage Level

Output Voltage Range (Notes 10, 11)

Adjustable Version
Fixed Version at 1.2 V
Fixed Version at 1.35 V

USB or 5 V Rail Powered Applications

V

V

OUT

FB

−

0.6

−

1.2

−

1.35

0.9

0.9−−

3.3

3.9

−

V

−

−

V

(VIN from 4.3 V to 5.5 V) (Note 12)

Output Voltage Accuracy Room Temperature (Note 13)

Overtemperature Range

Maximum Output Current (Note 10) I

Output Voltage Load Regulation
Overtemperature

Load Transient Response
Rise/Fall Time 1 ms

Load = 100 mA to 1000 mA (PWM Mode)
Load = 0 mA to 100 mA (PFM Mode)

10 mA to 100 mA Load Step
(PFM to PWM Mode)
200 mA to 600 mA Load Step

DV

OUT

OUTMAX

V

LOADR

V

LOADT

−−3$1$2−

+3

1 − − A

−−−0.9

1.1−−

−−40

85

−

mV

−

%

%

(PWM to PWM Mode)

Output Voltage Line Regulation Load = 100 mA VIN = 2.7 V to 5.5 V V

Line Transient Response Load = 100 mA

Output Voltage Ripple I

3.6 V to 3.2 V Line Step (Fall Time = 50 ms)

= 0 mA

OUT

I

= 300 mA

OUT

V

V

Switching Frequency F

LINER

LINET

RIPPLE

SW

− 0.05 − %

− 6.0 − mV

−−8.0

mV

3.0−−

1.2 1.7 2.2 MHz

PP

PP

Duty Cycle D − − 100 %

Soft−Start Time Time from EN to 90% of Output Voltage t

START

− 310 500

ms

POWER SWITCHES

High−Side MOSFET On−Resistance

Low−Side MOSFET On−Resistance R

High−Side MOSFET Leakage Current I

Low−Side MOSFET Leakage Current I

R

ONHS

ONLS

LEAKHS

LEAKLS

− 400 −

− 300 −

− 0.05 −

− 0.01 −

mW

mW

mA

mA

PROTECTION

DC−DC Short Circuit Protection

Thermal Shutdown Threshold T

Thermal Shutdown Hysteresis T

Peak Inductor Current I

PK

SD

SDH

− 1.6 − A

− 180 − °C

− 40 − °C

10.Functionality guaranteed per design and characterization.

11.Whole output voltage range is available for adjustable versions only. By topology, the maximum output voltage will be equal or lower than
the input voltage.

12.See chapter ”USB or 5 V Rail Powered Applications”.

13. For adjustable versions only, the overall output voltage tolerance depends upon the accuracy of the external resistor (R1 and R2). Specified
value assumes that external resistor have 0.1% tolerance.

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NCP1529

TABLE OF GRAPHS

Typical Characteristics for Step−down Converter Figure

h

I

q ON

I

q OFF

F

SW

V

LOADR

V

LOADT

V

LINER

V

LINET

t

START

I

PK

V

UVLO

VIL, V

P, G Phase & Gain Performance 24

Efficiency vs. Output Current 10, 11, 12

Quiescent Current, PFM no load vs. Input Voltage 9

Standby Current, EN Low vs. Input Voltage 8

Switching Frequency vs. Ambient Temperature 13

Load Regulation vs. Load Current 14

Load Transient Response 16, 17

Line Regulation vs. Output Current 15

Line Transient Response 18, 19

Soft Start 20

Short Circuit Protection 21

Under Voltage Lockout Threshold vs. Ambient Temperature 22

Enable Threshold vs. Ambient Temperature 23

IH

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