MICREL MIC23250, MIC23250-Adj Datasheet

General Description

MIC23250

4MHz Dual 400mA Synchronous Buck
Regulator with HYPER LIGHT LOAD™

Features

The MIC23250 is a high efficiency 4MHz dual 400mA
synchronous buck regulator with Hyper Light Load™. Hyper
Light Load™ provides all the advantages of standard light
load modes, such as low quiescent current and high
efficiency but also allows the use of very small output
capacitors to maintain low output ripple voltage throughout
the entire load range. This benefit is not possible with other
light load mode types as they trade off control speed for low
standby currents. With Hyper Light Load™, the output
capacitor can be reduced by up to a factor of 20 saving cost
and valuable board space. The tiny package (2mm x 2mm
Thin MLF

®

) of MIC23250 also saves crucial board space by
using only six external components while regulating two
independent outputs up to 400mA each.

The device is designed for use with a 1µH inductor and a

4.7µF output capacitor that enables a sub-1mm height.
The MIC23250 has a very low quiescent current of 35µA

and can achieve over 85% efficiency at 1mA. At higher
loads the MIC23250 provides a constant switching
frequency around 4MHz while providing peak efficiencies up
to 94%.

The MIC23250 fixed output voltage option is available in a
10-pin 2mm x 2mm Thin MLF

®

with a junction operating

range from –40°C to +125°C. The adjustable output voltage
option will soon be available in Q2/Q3 2008.

Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.

• Input voltage range: 2.7V to 5.5V

• Dual output current 400mA/400mA

• Hyper Light Load™ mode

– 35µA dual quiescent current
– 1µH inductor with a 4.7µF capacitor

• 4MHz in PWM operation

• Ultra fast transient response

• Low voltage output ripple

– 20mVpp in Hyper Light Load™ mode
– 3mV output voltage ripple in full PWM mode

• Up to 94% peak efficiency and 85% efficiency at 1mA

• Fully integrated MOSFET switches

• Micropower shutdown

• Thermal shutdown and current limit protection

• Fixed output:10-pin 2mm x 2mm Thin MLF

• Adjustable output:12-pin 2.5mm x 2.5mm Thin MLF

®

®

(Available in Q2/Q3 2008)

• –40°C to +125°C junction temperature range

Applications

• Mobile handsets

• Portable media players

• Portable navigation devices (GPS)

• WiFi/WiMax/WiBro modules

• Digital cameras

• Wireless LAN cards

• USB Powered Devices

___________________________________________________________________________________________________________

Typical Application

Hyper Light Load is a trademark of Micrel, Inc.

MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

December 2007

Efficiency V

100

VIN = 2.7V

90

80

70

VIN = 4.2V

60

50

40

30

20

10

0

1 10 100 1000

OUT

VIN = 3.0V

VIN = 3.6V

L = 1µH
C

LOAD (mA)

= 1.8V

OUT

= 4.7µF

408

) 944-0800 • fax + 1 [phone] • http://www.micrel.com

M9999-121707-A

Micrel, Inc. MIC23250

A

Ordering Information

Part Number Marking

MIC23250-GFHYMT WV1 1.575V 1.8V –40° to +125°C

MIC23250-G4YMT WV5 1.8V 1.2V –40° to +125°C

MIC23250-C4YMT WV2 1.0V 1.2V –40° to +125°C

MIC23250-3BYMT WV3 1.1V 0.9V –40° to +125°C

MIC23250-W4YMT WV4 1.6V 1.2V –40° to +125°C

MIC23250-Adj* TBD ADJ ADJ –40° to +125°C

Note: * Available Q2/Q3 2008

Nominal

Output

Voltage 1

Nominal

Output

Voltage 2

Junction

Temp. Range

Pin Configuration

1SNS1

EN1

2

10 SNS2

EN2

9

Package

10-Pin 2mm x 2mm

Thin MLF

10-Pin 2mm x 2mm

Thin MLF

10-Pin 2mm x 2mm

Thin MLF

10-Pin 2mm x 2mm

Thin MLF

10-Pin 2mm x 2mm

Thin MLF

12-Pin 2.5mm x

2.5mm Thin MLF

®

®

®

®

®

®

Lead

Finish

Pb-Free

Pb-Free

Pb-Free

Pb-Free

Pb-Free

Pb-Free

Pin Description

Pin Number Pin Name Pin Name

1 SNS1

2 EN1

3 AGND Analog Ground. Must be connected externally to PGND.

4 SW1 Switch Node 1 (Output): Internal power MOSFET output.

5 PGND Power Ground.

6 VIN Supply Voltage (Power Input): Requires close bypass capacitor to PGND.

7 SW2 Switch Node 2 (Output): Internal power MOSFET output.

8 AVIN Supply Voltage (Power Input): Analog control circuitry. Connect to VIN.

9 EN2

10 SNS2

GND

SW1

PGND VIN5

3

4

AVIN

8

SW2

7

6

10-Pin 2mm x 2mm Thin MLF® (MT)

(Top View)

Sense 1 (Input): Error amplifier input. Connect to feedback resistor network to
set output 1 voltage.

Enable 1 (Input): Logic low will shut down output 1. Logic high powers up
output 1. Do not leave unconnected.

Enable 2 (Input): Logic low will shut down output 2. Logic high powers up
output 2. Do not leave unconnected.

Sense 2 (Input): Error amplifier input. Connect to feedback resistor network to
set output 2 voltage.

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Micrel, Inc. MIC23250

Absolute Maximum Ratings

(1)

Operating Ratings

(2)

Supply Voltage (VIN)......................................................... 6V

Output Switch Voltage (V
Logic Input Voltage (V
Storage Temperature Range (T
ESD Rating

(3)

.................................................................. 2kV

) ............................................ 6V

SW

) ..................................–0.3V to VIN

EN

)..............–65°C to +150°C

s

Supply Voltage (VIN)......................................... 2.7V to 5.5V

Logic Input Voltage (V
Junction Temperature (T
Thermal Resistance
2mm x 2mm Thin MLF

) .................................. –0.3V to VIN

EN

) ..................–40°C  TJ  +125°C

J

®

-10 (θJA)........................70°C/W

Electrical Characteristics

T

= 25°C with VIN = VEN = 3.6V; L = 1µH; C

A

otherwise specified. Bold values indicate –40°C< T

Parameter Condition Min Typ Max Units

Supply Voltage Range 2.7 5.5 V

Under-Voltage Lockout Threshold (turn-on) 2.45 2.55 2.65 V

UVLO Hysteresis 60 mV
Quiescent Current,

Hyper LL mode

Shutdown Current V

Output Voltage Accuracy VIN = 3.6V, I

Current Limit in PWM Mode SNS = 0.9*V

Output Voltage Line Regulation VIN = 3.0V to 5.5V, I

Output Voltage Load Regulation 20mA < I

Maximum Duty Cycle

PWM Switch ON-Resistance

Frequency I

Soft Start Time V

Enable Threshold

Enable Input Current 0.1

Over-temperature Shutdown 160
Over-temperature Shutdown

Hysteresis

Notes:

1. Exceeding the absolute maximum rating may damage the device.

2. The device is not guaranteed to function outside its operating rating.

3. Devices are ESD sensitive. Handling precautions recommended. Human body model: 1.5k in series with 100pF.

4. Specification for packaged product only.

(4)

= 4.7µF; I

OUT

< +125°C.

J

V

OUT1, 2 (both Enabled)

, I

OUT1, 2

Nominal

= 0V; VIN = 5.5V 0.01

EN1, 2

= 20mA

LOAD

OUT NOM

LOAD

< 400mA, VIN = 3.6V 0.5 %

LOAD

SNS ≤ V

= 100mA PMOS

I

SW

= -100mA NMOS

I

SW

LOAD

OUT

, V

NOM

= 1.8V, VIN = 2.7V

OUT

= 120mA

= 90% 260 µs

= 20mA; only one channel power is enabled, unless

OUT

= 0mA , SNS1, 2 >1.2 * V

OUT1, 2

35 50 µA

4

–2.5

0.410

0.65

+2.5

1

µA

%

A

= 20mA 0.4 %/V

80

3.4

0.5

86 %

0.6

0.8

4

0.8

4.6

1.2
2




MHz

V

µA
°C

40

°C

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M9999-121707-A

Micrel, Inc. MIC23250

Typical Characteristics

Quiescent Current

vs. Input Voltage

50

45

40

35

30

25

20

15

10

5

0

2.7

3.2 3.7 4.2 4.7 5.2 5.7

5.0

4.5

4.0

3.5

3.0

1.9

1.8

1.7

1.6

1.5

700

650

600

550

2.7

3.2 3.7 4.2 4.7 5.2 5.7

December 2007

L = 1µH
C

= 4.7µF

OUT

INPUT VOLTAGE (V)

Frequency

vs. Temperature

L = 1µH
C

= 4.7µF

OUT

Load = 120mA

20 40 60 80

TEMPERATURE (°C)

Output Voltage

vs. Temperature

VOUT2 = 1.8V

L = 1µH
C

= 4.7µF

OUT

Load = 120mA

VOUT1 = 1.575V

20 40 60 80

TEMPERATURE (°C)

Current Limit

vs. Input Voltage

L = 1µH
C

= 4.7µF

OUT

INPUT VOLTAGE (V)

Switching Frequency

vs. Output Current

10

4MHz

VIN = 3.0V

1

0.1

VIN = 3.6V

0.01
1 10 100 1000

VIN = 4.2V

V

= 1.8V

OUT

L = 1µH
C

= 4.7µF

OUT

OUTPUT CURRENT (mA)

Output Voltage

1.90

1.88

1.86

1.84

1.82

1.80

1.78

1.76

1.74

1.72

1.70

vs. Output Current

VIN = 3.0V

VIN = 4.2V

VIN = 3.6V

1 10 100 1000

OUTPUT CURRENT (mA)

Enable Threshold

1.2

1.0

0.8

0.6

0.4

0.2

100

vs. Temperature

VIN = 3.6V

VIN = 5.5V

VIN = 2.7V

L = 1µH
C

= 4.7µF

0

TEMPERATURE (°C)

Efficiency V

VIN = 2.7V

90

80

70

VIN = 4.2V

60

50

40

30

20

10

0

1 10 100 1000

OUT

20 40 60 80

= 1.8V

OUT

VIN = 3.0V

VIN = 3.6V

L = 1µH
C

OUT

LOAD (mA)

= 4.7µF

1.000

0.975

0.950

0.925

0.900

0.875

0.850

0.825

0.800

Switching Frequency

vs. Output Current

10

L = 4.7µH

4MHz

1

0.1

0.01
1 10 100 1000

OUTPUT CURRENT (mA)

L = 1µH

L = 2.2µH

VIN = 3.6V
V

OUT

C

OUT

= 1.8V
= 4.7µF

Output Voltage

1.90

1.88

1.86

1.84

1.82

1.80

1.78

1.76

1.74

1.72

1.70

vs. Input Voltage

L = 1µH

= 4.7µF

C

OUT

Load = 10mA

Load = 50mA

Load = 400mA

3.2 3.7 4.2 4.7 5.2 5.7

2.7
INPUT VOLTAGE (V)

Load = 1mA

Load = 150mA

Load = 300mA

Enable Threshold
vs. Input Voltage

Enable ON

Enable OFF

VIN = 3.6V
V

= 1.8V

OUT

Load = 150mA

3.2 3.7 4.2 4.7 5.2 5.7

2.7
INPUT VOLTAGE (V)

Efficiency V

100

90

80

70

60

50

40

30

20

10

0

1 10 100 1000

L = 1.5µH

L = 1.0µH

LOAD (mA)

= 1.8V

OUT

L = 0.47µH

VIN = 3.6V
C

= 4.7µF

OUT

4

M9999-121707-A

Micrel, Inc. MIC23250

Typical Characteristics (Continued)

Efficiency V

100

VIN = 2.7V

90

80

70

VIN = 4.2V

60

50

40

30

20

10

0

1 10 100 1000

= 1.575V

OUT

VIN = 3.0V

VIN = 3.6V

L = 1µH
C

OUT

LOAD (mA)

= 4.7µF

Dual Output Efficiency

100

90

80

70

VIN = 3.6V

60

50

40

V
V

30

Load1 = Load2

20

L1 = L2 = 1µH

10

C

0

1 10 100 1000

OUT1
OUT2

OUT1

VIN = 3.3V

= 1.575V
= 1.8V

= C

OUT2

LOAD (mA)

VIN = 4.2V

= 4.7µF

December 2007

5

M9999-121707-A