ON Semiconductor NCP1526 Technical data

NCP1526

3 MHz, 400 mA, High−Efficiency, Step−Down Converter with Low Noise Voltage Regulator Optimized to Power Application Processor or RF Module

The NCP1526 is a monolithic integrated circuit combining a step−down PWM DC−DC converter and a low noise, low dropout voltage regulator. The device is dedicated to power RF sensitive module in portable applications from one Li−ion or three Alkaline / NiCd / NiMH batteries cells. The DC−DC converter offers fixed output voltage and delivers up to 400 mA. It uses synchronous rectification to increase efficiency and eliminates the external Schottky diode.

The device also has a built−in 3.0 MHz (nominal) oscillator which reduces component size by allowing the use of small inductor (down to 1 mH) and capacitors. Additional features include integrated soft−start, cycle−by−cycle current limiting, and thermal shutdown protection. The integrated very low noise, low dropout regulator is available with 150 mA current capability, current limitation and temperature limit protection.

The NCP1526 is available in a space saving, ultra low profile 3x3 mm, 10 pin UDFN package (thickness 0.55 mm max).

Features

• Step−Down Converter

− Up to 94% Efficiency (85% at 1.2 V)

− Output Current Capability 400 mA

− 3.0 MHz Switching Frequency

− Fixed Output Voltage (1.2 V available now, other voltages available upon request) (see page 13)

− Synchronous Rectification for Higher Efficiency

• LDO Regulator

− Fixed Output Voltage (2.8 V available now, other voltages available upon request) (see page 13)

− Up to 150 mA Output Current Capability

− Very Low Noise: 45 mV

• All Pins are Fully ESD Protected

• 2.7 V to 5.2 V Input Voltage Range

• Thermal Limit Protection

• 3.0 mm x 3.0 mm x 0.55 mm UDFN Package

• This is a Pb−Free Device

RMS

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MARKING DIAGRAM

10 PIN DFN MU SUFFIX

CASE 506AT

1526 = Specific Device Code A = Assembly Location L = Wafer Lot Y = Year W = Work Week G = Pb−Free Package

(Note: Microdot may be in either location)

PIN CONNECTIONS

FB EN1 EN2

GND2

BYPASS

(Top View)

ORDERING INFORMATION

Device Package Shipping

NCP1526MUTXG UDFN−10

(Pb−Free)

†For information on tape and reel specifications,

including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D.

1526

ALYWG

VIN1 LX GND1 VIN2 V1

3000/Tape & Ree

†

T ypical Applications

• Cellular Phones, Smart Phones and PDAs

• Digital Still Cameras

• MP3 Players and Portable Audio Systems

• Wireless and DSL Modems

• Portable Equipment

November, 2006 − Rev . 2

1 Publication Order Number:

NCP1526/D

NCP1526

Vbattery

OFF ON

EN1

EN2

BUCK

out

LDO

out

OFF ON OFF ON

BUCK

LDO

1 2 3 4 5

FB EN1 EN2 GND2 BYPASS

VIN1

GND1

VIN2

9 8 7 6

Figure 1. Typical Applications Circuit

Vbattery

ILIMIT

VIN1

REFERENCE

VIN2

VOLTAGE

VIN1

LOGIC

CONTROL

Buck Converter

PWM

CONTROL

VIN1

GND1

4.7 mF

2.2 mH

4.7 mF

out

BUCK

1.20 V ,

400 mA

100 nF

GND2

BYPASS

LOGIC

CONTROL

LDO

V1 BLOCK

Thermal

Shutdown

Vbattery

VIN2

4.7 mF V

LDO

out

2.80 V , 150 mA

1 mF

Figure 2. Simplified Block Diagram

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NCP1526

PIN FUNCTION DESCRIPTION (Pin out provided for concept purpose only and might change in the final product.)

Pin No. Symbol Function Description

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

2 EN1 Digital Input Enable for DC−DC converter. This pin is active high. It is turned of f by logic

3 EN2 Digital Input EN2 enables the LDO.A HIGH level on this pin activates the voltage

4 GND2 Power Ground Ground connection for the LDO section and must be connected to the

5 BYPASS Bypass is the bandgap reference for the LDO. This pin requires a 100 nF

6 V1 Output Power This pin provides the output voltage supplied by the LDO. This pin requires

7 VIN2 Power Input Input battery voltage to supply voltage regulator blocks. The pin requires a

8 GND1 Power Ground This pin is the GROUND reference for the DC−DC converter and the output

9 LX Analog Output Connection from Power MOSFETs to the inductor. An output discharge

10 VIN1 Power Input Input battery voltage to supply the analog and digital blocks of the DC−DC

the error amplifier.

LOW on this pin. Do not float this pin.

regulator. It is turned off by logic LOW on this pin. Do not float this pin.

system ground.

bypass capacitor for low noise. This pin cannot be used for an external source.

1.0 mF decoupling capacitor.

4.7 mF decoupling capacitor.

control. The pin must be connected to the system ground.

circuit sinks current from this pin.

converter. The pin must be decoupled to ground by a 4.7 mF ceramic capacitor.

MAXIMUM RATINGS

Rating Symbol Value Unit

Minimum Voltage All Pins V Maximum Voltage All Pins (Note 2) V Maximum Voltage EN1, EN2, FB, LX V UDFN10 Package (Note 5)

min max max

Thermal Resistance, Junction−to−Air Operating Ambient Temperature Range T Storage Temperature Range T Junction Operating Temperature T Latch−up Current Maximum Rating (TA = 85°C) (Note 4) FB pin

stg

Lu "70

Latch−up Current Maximum Rating (TA = 85°C) (Note 4) Other pins

ESD Withstand Voltage (Note 3)

Vesd Human Body Model Machine Model

Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.

1. Maximum electrical ratings are defined as those values beyond which damage to the device may occur at TA = 25°C.

2. According to JEDEC standard JESD22−A108B.

3. 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.

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

5. The exposed flag shall be connected to ground.

6. Moisture Sensitivity Level (MSL): 1 per IPC/JEDEC standard: J−STD−020A.

−0.3 V

7.0 V

VIN + 0.3 V

240 °C/W

−40 to 85 _C

−55 to 150 _C

−40 to 125 _C mA

"100

2.0

200

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NCP1526

ELECTRICAL CHARACTERISTICS, DC/DC Converter (Typical values are referenced to T

= +25°C, Min and Max values are

referenced −40°C to +85°C ambient temperature, unless otherwise noted, operating conditions VIN = 3.6 V , unless otherwise noted.)

Characteristic Pin Symbol Min Typ Max Unit

VIN1 PIN

Input Voltage Range 10 V Quiescent Current, I

Quiescent Current, I Quiescent Current, EN Low 8 I

= 0 mA, No Switching

out

= 0 mA, Oscillator Running

out

8 I

q OFF

Undervoltage Lockout (VIN Increase) 10 V Undervoltage Lockout Hysteresis 10 V

HUVLO

q ON

UVLO

2.7 − 5.2 V

−

250

2.5

350

−

− 0.2 1.5 mA

− 2.5 − V

− 100 − mV

EN1, EN2 PIN

Positive Going Input High Voltage Threshold, EN0 Signal 2, 3 V Negative Going Input High Voltage Threshold, EN0 Signal 2, 3 V

1.2 − − V

− − 0.4 V

DC−DC CONVERTER SECTION

Peak Inductor Current 9 I Feedback Voltage Threshold

1 V

Overtemperature

Load Transient Response, Rise/Fall Time 1.0 ms

− V

1.0 mA to 300 mA Load Step

1.0 mA to 400 mA Load Step Line Transient Response, I Output Voltage Load Regulation

= 1.0 mA to 300 mA

out

= 1.0 mA to 400 mA

out

Output Voltage Line Regulation, I Output Voltage Ripple, I

= 100 mA, 3.0 V to 3.6 V Line Step − V

out

− V

= 100 mA, VIN = 2.7 V to 5.2 V − V

out

= 300 mA − V

out

Oscillator Frequency 9 F

LIM

OUT

OUT OUT

OUT OUT OSC

− 1000 − mA

1.164 1.2 1.236

−

30 35

−

− "5.0 − mVpp

−

0.2

0.5

−

− 0.1 − %

− 5.0 − mV

2.4 3.0 3.6 MHz P−Ch On−Resistance 1 RLxH − 400 − mW N−Ch On−Resistance 1 RLxL − 400 − mW P−Ch Leakage Current 1 ILeakH − 0.05 − mA N−Ch Leakage Current 1 ILeakL − 0.01 − mA Soft−Start Time − Tstart − 100 300 ms

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NCP1526

ELECTRICAL CHARACTERISTICS for LDO (Typical values are referenced to T

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

−40°C to +85°C ambient temperature, unless otherwise noted, operating conditions 3 V < VIN < 5.2 V , unless otherwise noted.)

Characteristic Pin Symbol Min Typ Max Unit

VIN2 PIN

Input Voltage Range 7 V Quiescent Current On State

VIN2 = 4.2 V , I

out

= 0 mA

Quiescent Current Off State 4 I

4 I

q OFF

q ON

3 − 5.2 V

− 70 95 mA

− 0.2 − mA

LDO SECTION

Output Voltage, I Maximum Output Current 6 I Output Voltage Line Regulation, I Load Regulation, I Power Supply Ripple Rejection on V1, (0.2 Vp−p),

= 1.0 mF, Vin = 3.6 V

out

1.0 kHz I

out1

100 kHz, I

Dropout Voltage, I

= 0 mA to 150 mA 6 V1 2.716 2.80 2.884 V

out

= 10 mA 6 V1 − 10 − mV

out

= 1.0 mA to 150 mA, VIN = 3.6 V 6 V1 − 20 − mV

out

150 − − mA

6 PSRR

= 100 mA

out1

= 150 mA VINA−V1 − − 150 mV

out

−

67 45

−

Output Short Circuit Current 6 ISC 250 300 − mA Output Noise Voltage, 100 Hz to 100 kHz, I

= 10 mA, C

out

= 1.0 mF 6 V

out

− 45 − mVrms

Turn ON Output V oltage, Vin = 3.6 V 6 Ton − 80 150 ms

BYPASS PIN

Output Voltage, Cby = 100 nF 5 V

− 1.5 − V

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NCP1526

T ABLE OF GRAPHS

TYPICAL CHARACTERISTICS FOR STEP DOWN CONVERTER FIGURE

h Efficiency

OUT

OSC

OUT

Tstart Soft Start 11

Output Voltage vs. Temperature 6 Frequency Variation vs. Input Voltage 7 Load Regulation vs. Load Current 5 Load Transient Response 12

Line Regulation

Line Transient Response 14 PWM Mode Operation 13

TYPICAL CHARACTERISTICS

NCP1526 circuit on Figure 2, Vin = 3.6 V , TA = 25°C, unless otherwise noted

vs. Load Current 3, 4

vs. Input Voltage 8

vs. Ouptput Current 9 vs. Temperature 10

100

Vin = 2.7 V

EFFICIENCY (%)

STEP DOWN CONVERTER

40 30

Figure 3. Step Down Converter Efficiency vs.

3.0

2.0

1.0

−1.0

LOAD REGULATION (%)

STEP DOWN CONVERTER

−2.0

100

Vin = 3.6 V

Vin = 5.2 V

4003002001000

, OUTPUT CURRENT (mA) I

out

EFFICIENCY (%)

STEP DOWN CONVERTER

40 30

Figure 4. Step Down Converter Efficiency vs.

Output Current

1.225

TA = 25°C

TA = −40°C

1.215

TA = 85°C

Vin = 3.6 V

1.205

Temperature V

Vin = 2.7 V

Vin = 5.2 V

TA = 25°C

(mA)

out

= 3.6 V

TA = −40°C

TA = 85°C

4003002001000

−3.0

(mA) TEMPERATURE (°C)

out

Figure 5. Step Down Converter Load

Regulation vs. Temperature V

= 3.6 V

1.195

4003002001000

STEP DOWN CONVERTER OUTPUT VOLTAGE (V)

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Figure 6. Step Down Converter Output Voltage

vs. T emperature at I

= 100 mA

out

1251007550250−25−50

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