MIC2177YWM-TR

MIC2177YWM-TR Datasheet

MIC217777

Part	Datasheet
MIC2177YWM-TR	MIC2177YWM-TR (pdf)

Related Parts	Information
MIC2177-5.0YWM	MIC2177-5.0YWM
MIC2177YWM	MIC2177YWM
MIC2177-5.0YWM-TR	MIC2177-5.0YWM-TR

PDF Datasheet Preview
MIC217777 MicreMl,icInrecl. MIC2177 2.5A Synchronous Buck Regulator The Micrel MIC2177 is a 200kHz synchronous buck stepdown switching regulator designed for high-efficiency, battery-powered applications. The MIC2177 operates from a 4.5V to 16.5V input and features internal power MOSFETs that can supply up to 2.5A output current. It can operate with a maximum duty cycle of 100% for use in low-dropout conditions. It also features a shutdown mode that reduces quiescent current to less than 5µA. The MIC2177 achieves high efficiency over a wide output current range by switching between PWM and skip mode. Operating mode is automatically selected according to output conditions. Switching frequency is preset to 200kHz and can be synchronized to an external clock signal of up to 300kHz. The MIC2177 uses current-mode control with internal current sensing. Current-mode control provides superior line regulation and makes the regulator control loop easy to compensate. The output is protected with pulse-by-pulse current limiting and thermal shutdown. Undervoltage lockout turns the output off when the input voltage is less than 4.5V. The MIC2177 is packaged in a 20-lead wide power SO package with an operating temperature range of to +85°C. See the MIC2178 for externally selected PWM or skip-mode operation. • 4.5V to 16.5V input voltage range • Dual-mode operation for high efficiency up to 96% PWM mode for > 200mA load current Skip mode for < 200mA load current • internal power MOSFETs at 12V input • 200kHz preset switching frequency • Low quiescent current 1.0mA in PWM mode 500µA in skip mode < 5µA in shutdown mode • 100% duty cycle for low dropout operation • Current-mode control Simplified loop compensation Superior line regulation • Current limit • Thermal shutdown • Undervoltage lockout • High-efficiency, battery-powered supplies • Buck step-down dc-to-dc converters • Cellular telephones • Laptop computers • Hand-held instruments • Battery Charger VIN 5.4V to 18V C1 22µF 35V ENABLE SHUTDOWN 1,2,9 20 EN OUT 10 18 SYNC PGND 11 AUTO FB 12 COMP SGND BIAS 10k CC 6.8nF C3 0.01µF L1, 50µH D1 MBRS130L R1 10k VOUT 5V/1A C2 100µF 10V EFFICIENCY % 5V Output Efficiency VIN = 6V 75 70 SKIP PWM 1000 2500 OUTPUT CURRENT mA Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 408 944-0800 • fax + 1 408 474-1000 • March 2005 M9999-031805 Ordering Information Output Switching Temperature Voltage Frequency Range Package Lead Finish MIC2177-3.3BWM* MIC2177-5.0BWM* MIC2177BWM* MIC2177-3.3YWM MIC2177-5.0YWM MIC2177YWM 3.3V 5.0V adj. 3.3V 5.0V adj. 200kHz to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C 20-lead WSOP 20-lead WSOP 20-lead WSOP 20-lead WSOP 20-lead WSOP 20-lead WSOP Standard Pb-Free Pb-Free Pb-Free * Standard product will be supported as Pb-Free IAW PPCN #040004 effective 1-1-2005 pending residual depletion., Pin Configuration Micrel, Inc. Pin Description Pin Number 1, 2, 9 3,8 4,5,6,7 10 11 13 14,15,16,17 19 20 M9999-031805 VIN 1 VIN 2 SW 3 PGND 4 PGND 5 PGND 6 PGND 7 SW 8 VIN 9 OUT 10 20 EN 19 BIAS 18 SYNC 17 SGND 16 SGND 15 SGND 14 SGND 13 COMP 12 FB 11 AUTO 20-Lead Wide SOP Pin Name VIN SW PGND OUT AUTO COMP SGND SYNC BIAS EN Pin Function Supply Input Controller and switch supply. Unregulated supply input to internal regulator, output switches, and control circuitry. Requires bypass capacitor to PGND. All three pins must be connected to VIN. Switch Output Internal power MOSFET switch output. Both pins must be externally connected together. Power Ground Output stage ground connections. Connect all pins to a common ground plane. Output Voltage Sense Input Senses output voltage to determine minimum switch current for PWM operation. Connect directly to VOUT. Automatic Mode Connect 2.2nF timing capacitor for automatic PWM-/skipmode switching. Regulator operates exclusively in PWM mode when pin is pulled low. Feedback Input Error amplifier inverting input. For adjustable output version, connect FB to external resistive divider to set output voltage. For 3.3V and 5V fixed output versions, connect FB directly to output. Compensation Internal error amplifier output. Connect to capacitor or series RC network to compensate the regulator control loop. Signal Ground connection of control section. Connect all pins to common ground plane. Frequency Synchronization Input Optional clock input. Connect to external clock signal to synchronize oscillator. Leading edge of signal above 1.7V terminates switching cycle. Connect to SGND if not used. Bias Supply Internal 3.3V bias supply output. Decouple with 0.01µF bypass capacitor and to SGND. Do not apply any external load. Enable Input Logic high enables operation. Logic low shuts down regulator. Do not allow pin to float. March 2005 MIC2177

PDF Datasheet Preview

MIC217777

MicreMl,icInrecl.

MIC2177
2.5A Synchronous Buck Regulator

The Micrel MIC2177 is a 200kHz synchronous buck stepdown switching regulator designed for high-efficiency, battery-powered applications.

The MIC2177 operates from a 4.5V to 16.5V input and features internal power MOSFETs that can supply up to 2.5A output current. It can operate with a maximum duty cycle of 100% for use in low-dropout conditions. It also features a shutdown mode that reduces quiescent current to less than 5µA.

The MIC2177 achieves high efficiency over a wide output current range by switching between PWM and skip mode. Operating mode is automatically selected according to output conditions. Switching frequency is preset to 200kHz and can be synchronized to an external clock signal of up to 300kHz.

The MIC2177 uses current-mode control with internal current sensing. Current-mode control provides superior line regulation and makes the regulator control loop easy to compensate. The output is protected with pulse-by-pulse current limiting and thermal shutdown. Undervoltage lockout turns the output off when the input voltage is less than 4.5V.

The MIC2177 is packaged in a 20-lead wide power SO package with an operating temperature range of to +85°C.

See the MIC2178 for externally selected PWM or skip-mode operation.
• 4.5V to 16.5V input voltage range
• Dual-mode operation for high efficiency up to 96%

PWM mode for > 200mA load current Skip mode for < 200mA load current
• internal power MOSFETs at 12V input
• 200kHz preset switching frequency
• Low quiescent current 1.0mA in PWM mode 500µA in skip mode < 5µA in shutdown mode
• 100% duty cycle for low dropout operation
• Current-mode control Simplified loop compensation Superior line regulation
• Current limit
• Thermal shutdown
• Undervoltage lockout
• High-efficiency, battery-powered supplies
• Buck step-down dc-to-dc converters
• Cellular telephones
• Laptop computers
• Hand-held instruments
• Battery Charger

VIN 5.4V to 18V

C1 22µF 35V

ENABLE

SHUTDOWN
1,2,9
20 EN

OUT 10
18 SYNC

PGND
11 AUTO

FB 12

COMP SGND BIAS
10k CC 6.8nF

C3 0.01µF

L1, 50µH D1 MBRS130L

R1 10k

VOUT
5V/1A C2 100µF 10V

EFFICIENCY %
5V Output Efficiency

VIN = 6V
75 70

SKIP PWM
1000 2500

OUTPUT CURRENT mA

Micrel, Inc.
• 2180 Fortune Drive
• San Jose, CA 95131
• USA
• tel + 1 408 944-0800
• fax + 1 408 474-1000
•

March 2005

M9999-031805
Ordering Information

Output Switching Temperature

Voltage Frequency

Range

Package

Lead Finish

MIC2177-3.3BWM* MIC2177-5.0BWM* MIC2177BWM* MIC2177-3.3YWM MIC2177-5.0YWM MIC2177YWM
3.3V 5.0V adj. 3.3V 5.0V adj.
200kHz
to +85°C to +85°C to +85°C to +85°C to +85°C to +85°C
20-lead WSOP 20-lead WSOP 20-lead WSOP 20-lead WSOP 20-lead WSOP 20-lead WSOP

Standard Pb-Free Pb-Free Pb-Free
* Standard product will be supported as Pb-Free IAW PPCN #040004 effective 1-1-2005 pending residual depletion.,

Pin Configuration

Micrel, Inc.

Pin Description

Pin Number 1, 2, 9
3,8 4,5,6,7
10 11
13 14,15,16,17
19 20

M9999-031805

VIN 1 VIN 2 SW 3 PGND 4 PGND 5 PGND 6 PGND 7 SW 8 VIN 9 OUT 10
20 EN 19 BIAS 18 SYNC 17 SGND 16 SGND 15 SGND 14 SGND 13 COMP 12 FB 11 AUTO
20-Lead Wide SOP

Pin Name VIN

SW PGND OUT AUTO

COMP SGND SYNC

BIAS EN

Pin Function

Supply Input Controller and switch supply. Unregulated supply input to internal regulator, output switches, and control circuitry. Requires bypass capacitor to PGND. All three pins must be connected to VIN. Switch Output Internal power MOSFET switch output. Both pins must be externally connected together.

Power Ground Output stage ground connections. Connect all pins to a common ground plane.

Output Voltage Sense Input Senses output voltage to determine minimum switch current for PWM operation. Connect directly to VOUT. Automatic Mode Connect 2.2nF timing capacitor for automatic PWM-/skipmode switching. Regulator operates exclusively in PWM mode when pin is pulled low.

Feedback Input Error amplifier inverting input. For adjustable output version, connect FB to external resistive divider to set output voltage. For 3.3V and 5V fixed output versions, connect FB directly to output.

Compensation Internal error amplifier output. Connect to capacitor or series RC network to compensate the regulator control loop.

Signal Ground connection of control section. Connect all pins to common ground plane.

Frequency Synchronization Input Optional clock input. Connect to external clock signal to synchronize oscillator. Leading edge of signal above 1.7V terminates switching cycle. Connect to SGND if not used.

Bias Supply Internal 3.3V bias supply output. Decouple with 0.01µF bypass capacitor and to SGND. Do not apply any external load.

Enable Input Logic high enables operation. Logic low shuts down regulator. Do not allow pin to float.

March 2005

MIC2177

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Datasheet ID: MIC2177YWM-TR 648140