MCP16321T-250E_技术文档

MCP16321/2

24V Input, 1A/2A Output, High Efficiency Synchronous Buck Regulator

with Power Good Indication

Features

Description

• Up to 95% Typical Efficiency

• Input Voltage Range: 6.0V to 24V

• 1A Output Current (MCP16321)

• 2A Output Current (MCP16322)

The MCP16321/2 is a highly integrated, high-efficiency,

fixed frequency, synchronous step-down DC-DC

converter in a 16-pin QFN package that operates from

input voltages up to 24V. Integrated features include a

high-side and low-side N-Channel switch, fixed

frequency Peak Current Mode Control, internal

compensation, peak current limit, V_OUTovervoltage

protection and overtemperature protection. Minimal

external components are necessary to develop a

complete synchronous step-down DC-DC converter

power supply.

• Fixed Output Voltages: 0.9V, 1.5V, 1.8V, 2.5V,

3.3V, 5V with 2% Output Voltage Accuracy

• Adjustable Version Output Voltage Range:

0.9V to 5V with 1.5% Reference Voltage Accuracy

• Integrated N-Channel High-Side Switch: 180 mΩ

• Integrated N-Channel Low-Side Switch: 120 mΩ

• 1 MHz Fixed Frequency

High converter efficiency is achieved by integrating a

high-speed, current limited, low resistance, high-side

N-Channel MOSFET, as well as a high-speed, low

resistance, low-side N-Channel MOSFET and

associated drive circuitry. High switching frequency

minimizes the size of the inductor and output capacitor,

resulting in a small solution size.

• Low Device Shutdown Current

• Peak Current Mode Control

• Internal Compensation

• Stable with Ceramic Capacitors

• Internal Soft-Start

• Cycle-by-Cycle Peak Current Limit

• Undervoltage Lockout (UVLO): 5.75V

• Overtemperature Protection

The MCP16321/2 device can supply 1A/2A of

continuous current while regulating the output voltage

from 0.9V to 5V. A high-performance peak current

mode architecture keeps the output voltage tightly

regulated, even during input voltage steps and output

current transient conditions that are common in power

supplies.

• V_OUTOvervoltage Protection

• V_OUTVoltage Supervisor Reported at the PG Pin

• Available Package: QFN-16 (3x3 mm)

The regulator can be turned on and off with a logic level

signal applied to the EN input. The EN input is internally

pulled up to a 4.2V reference and is rated for a

maximum of 6V. With EN low, typically 5 µA of current

is consumed from the input, making the part ideal for

power shedding and load distribution applications. The

PG output is an open drain output pin used to interface

with other components of the system, and can be

pulled up to a maximum of 6V.

Applications

• PIC^®/dsPIC^®Microcontroller Bias Supply

• 12V Industrial Input DC-DC Conversion

• Set-Top Boxes

• DSL Cable Modems

• Automotive

• Wall Cube Regulation

• SLA Battery Powered Devices

• AC-DC Digital Control Power Source

• Power Meters

The output voltage can either be fixed at output

voltages of 0.9V, 1.5V, 1.8V, 2.5V, 3.3V, 5V or

adjustable using an external resistor divider. The

MCP16321/2 is offered in a 3x3 QFN-16 surface mount

package.

• Consumer

• Medical and Health Care

• Distributed Power Supplies

DS22285A-page 1

MCP16321/2

Package Type

MCP16321/2

3x3 QFN*

16 15 14 13

SW

1

12

11

10

9

V

2

3

4

IN

EP

17

BOOST

EN

V

IN

S

GND

5

6

7

8

* Includes Exposed Thermal Pad (EP); see Table 3-1.

Typical Applications

Typical Application with Adjustable Output Voltage

C_BOOST

22 nF

L1

BOOST

V_OUT

4.7 μH

4.2V @ 1A/2A

V_IN

SW

V_FB

6.0V to 24V

V_IN

EN

36.5 kꢀ

C_OUT

2x22 μF

V_OUT

10 kꢀ

C_IN

2x10 μF

PG

S_GND

P_GND

Typical Application with Fixed Output Voltage

C_BOOST

22 nF

L1

4.7 μH

V_OUT

BOOST

3.3V @ 1A/2A

V_IN

SW

V_FB

6.0V to 24V

V_IN

EN

C_OUT

2x22 μF

V_OUT

10 kꢁ

C_IN

2x10 μF

PG

S_GND

P_GND

DS22285A-page 2

MCP16321/2

† Notice: Stresses above those listed under “Absolute

Maximum Ratings” may cause permanent damage to

the device. This is a stress rating only and functional

operation of the device at those or any other conditions

above those indicated in the operational sections of this

specification is not intended. Exposure to maximum

rating conditions for extended periods may affect

device reliability.

1.0

ELECTRICAL

CHARACTERISTICS

Absolute Maximum Ratings†

V

.................................................................... -0.3V to 26.4V

IN

SW ...................................................................... -1V to 26.4V

BOOST – GND ........................................... -0.3V to (V +6V)

IN

EN,V , PG Voltage.............................................. -0.3V to 6V

FB

Continuous Total Power Dissipation .......................................

...................................................See Thermal Characteristics

Storage Temperature ....................................-65°C to +150°C

Operating Junction Temperature...................-40°C to +125°C

ESD Protection On All Pins:

HBM .........................................................................3 kV

MM ..........................................................................200V

DC CHARACTERISTICS

Electrical Characteristics: Unless otherwise indicated, T_A= +25°C, V_IN= 12V, V_OUT= 3.3V, I_OUT= 300 mA,

L = 4.7 µH, C_OUT= 2x22 µF, C_IN= 2x10 µF. Boldface specifications apply over the T_Jrange of -40°C to +125°C.

Parameters

Sym

Min

Typ

Max

Units

Conditions

V_INSupply Voltage

Input Voltage

V_IN

I_Q

6.0

—

24

V

Quiescent Current

(Switching)

—

5.2

—

mA I_OUT= 0 mA

Quiescent Current

(Non-Switching)

I_Q

—

2.3

5

—

mA Closed Loop in

Overvoltage

I_OUT= 0 mA

Quiescent Current -

Shutdown

I_Q

10

µA EN = 0

V_INUndervoltage Lockout

Undervoltage Lockout Start

UVLO_STRT

UVLO_HYS

5.5

5.75

0.65

6.0

V

V_INRising

Undervoltage Lockout

Hysteresis

—

Non-Switching

Output Characteristics

Maximum Output Current

MCP16321

I_OUT

1

2

—

A

V_IN= 6V to 24V

Maximum Output Current

MCP16322

Output Voltage Adjust Range

V_OUT

0.9

—

5.0

V

Output Voltage Tolerance

in PWM Mode

V_OUT-PWM

V_OUT- 2%

V_OUT

V_OUT+ 2%

I_OUT= 1A

I_OUT= 0A

Output Voltage Tolerance

in PFM Mode

V_OUT-PFM

V_OUT- 1% V_OUT+ 1% V_OUT+ 3.5%

V

Feedback Voltage

V_FB

0.886

-1.5

0.9

—

0.914

1.5

V

Feedback Reference

Tolerance

V_FB-TOL

%

PFM Mode Feedback

Comparator Threshold

V_FB-PFM

I_FB

—

V_OUT+ 1%

100

—

V

Feedback Input Bias

Current

nA

Note 1: Regulator SW pin is forced off for 240 ns every 8 cycles to ensure the BOOST cap is replenished.

DS22285A-page 3

MCP16321/2

DC CHARACTERISTICS (CONTINUED)

Electrical Characteristics: Unless otherwise indicated, T_A= +25°C, V_IN= 12V, V_OUT= 3.3V, I_OUT= 300 mA,

L = 4.7 µH, C_OUT= 2x22 µF, C_IN= 2x10 µF. Boldface specifications apply over the T_Jrange of -40°C to +125°C.

Parameters

Sym

Min

Typ

Max

Units

Conditions

PFM Mode Feedback

EN Input Characteristics

EN Input Logic High

V_FB-PFM

—

V_OUT+ 1%

—

V

V_IH

V_IL

2.2

—

0.8

—

V

EN Input Logic Low

EN Input Hysteresis

V_EN-HYST

I_ENLK

480

3.5

-1.5

4

mV

EN Input Leakage Current

µA V_EN= 5V

µA V_EN= 0V

ms

Soft-Start Time

t_SS

Switching Characteristics

Switching Frequency

f_SW

0.9

95

1

1.1

99

MHz Open Loop V_FB

Low

Maximum Duty Cycle

DC_MAX

97

%

Open Loop V_FB

Low

Note 1

Minimum Duty Cycle

—

7

—

%

NMOS Low-Side

Low-Side R_DS(ON)

120

mΩ

Switch On Resistance

NMOS High-Side

Switch On Resistance

High-Side

R_DS(ON)

—

180

—

mΩ

NMOS High-Side

Switch Current Limit

I_N(MAX)

1.4

2.4

1.8

2.8

2.4

3.4

A

MCP16321

MCP16322

PG Output Characteristics

PG Low-level

Output Voltage

PG_IL

—

0.5

10

0.01

V

I_PG= -0.3 mA

PG High-Level Output Leak-

age Current

I_PGLK

—

µA V_PG= 5V

ms

PG Release Timer

t_PG

—

95% V_OUT

—

V_OUTUndervoltage Threshold

V_OUT-UV

91% V_OUT93% V_OUT

V_OUTUndervoltage

Hysteresis

V_{OUT-UV_HYST}

—

1.5% V_OUT

103% V_OUT

1% V_OUT

V

_OUTOvervoltage

Threshold

_OUTOvervoltage

V_OUT-OV

—

V

V_{OUT-OV_HYST}

Hysteresis

Thermal Characteristics

Thermal Shutdown

Die Temperature

T_SD

—

170

10

—

°C

Die Temperature

Hysteresis

T_SDHYS

Note 1: Regulator SW pin is forced off for 240 ns every 8 cycles to ensure the BOOST cap is replenished.

DS22285A-page 4

MCP16321/2

TABLE 1-1:

TEMPERATURE CHARACTERISTICS

Electrical Characteristics

Parameters

Sym

Min

Typ

Max

Units

Conditions

Temperature Ranges

Operating Junction Temperature

Range

T_J

-40

—

125

°C

Steady State

Storage Temperature Range

T_A

T_J

-65

—

150

°C

Maximum Junction Temperature

Package Thermal Resistances

Thermal Resistance, 16L 3x3-QFN

Transient

θ_JA

—

38.5

—

°C/W Note 1

Note 1: Measured using a 4-layer FR4 Printed Circuit Board with a 13.5 in², 1 oz internal copper ground plane.

DS22285A-page 5

MCP16321/2

NOTES:

DS22285A-page 6

MCP16321/2

2.0

TYPICAL PERFORMANCE CURVES

Note:

The graphs and tables provided following this note are a statistical summary based on a limited number of

samples and are provided for informational purposes only. The performance characteristics listed herein

are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified

operating range (e.g., outside specified power supply range) and therefore outside the warranted range.

Note: Unless otherwise indicated, V_IN= 12V, EN = Floating (Internally pulled up), C_IN= 20 µF, C_OUT= 2x22 µF,

L = 4.7 µH (XAL6060-472MEB), I_LOAD= 200 mA, T_A= +25°C. MCP16321 maximum output current = 1A.

100

95

90

85

80

75

70

65

60

55

50

100

90

80

70

60

50

40

V_IN= 6V

V_IN= 12V

V_IN= 18V

V_IN= 24V

V_IN= 12V

V_IN= 18V

V_OUT= 5V

V_OUT= 1.8V

0.0

0.4

0.8

1.2

I_OUT(A)

1.6

2.0

0

0.4

0.8

1.2

I_OUT(A)

1.6

2

FIGURE 2-1:

5V V_OUTEfficiency vs. I_OUT

.

FIGURE 2-4:

I_OUT

1.8V V_OUTEfficiency vs.

.

90

85

80

75

70

65

60

55

50

45

40

95

V_IN= 6V

90

85

80

75

70

65

60

V_IN= 12V

V_IN= 18V

V_OUT= 3.3V

V_OUT= 1.5V

V_IN= 24V

55

50

0

0.4

0.8

1.2

I_OUT(A)

1.6

2

0

0.4

0.8

1.2

I_OUT(A)

1.6

2

FIGURE 2-2:

3.3V V_OUTEfficiency vs.

FIGURE 2-5:

1.5V V_OUTEfficiency vs.

I_OUT.

100

90

100

V_IN= 6V

90

80

70

60

50

40

V_IN= 6V

80

70

60

50

40

V_IN= 12V

V_IN= 8V

V_IN= 18V

V_OUT= 0.9V

V_OUT= 2.5V

V_IN= 24V

V_IN= 10V

0.4

0

0.4

0.8

1.2

I_OUT(A)

1.6

2

0

0.8

1.2

I_OUT(A)

1.6

2

FIGURE 2-3:

2.5V V_OUTEfficiency vs.

FIGURE 2-6:

0.9V V_OUTEfficiency vs.

I_OUT.

DS22285A-page 7

MCP16321/2

Note: Unless otherwise indicated, V_IN= 12V, EN = Floating (Internally pulled up), C_IN= 20 µF, C_OUT= 2x22 µF,

L = 4.7 µH (XAL6060-472MEB), I_LOAD= 200 mA, T_A= +25°C. MCP16321 maximum output current = 1A.

5.04

5.03

5.02

5.01

5

1.808

1.807

1.806

1.805

1.804

1.803

1.802

1.801

1.8

V_OUT= 5V

V_OUT=1.8V

V_IN= 6V

V_IN= 12V

V_IN= 18V

1.6

V_IN= 24V

4.99

4.98

V_IN= 18V

1.799

1.798

0

0.4

0.8

1.2

I_OUT(A)

2

0

0.4

0.8

I_OUT(A)

1.2

1.6

2

FIGURE 2-7:

5V V_OUTvs. I_OUT.

FIGURE 2-10:

1.8V V_OUTvs. I_OUT.

3.32

3.315

3.31

1.505

1.504

1.503

1.502

1.501

1.5

V_OUT=1.5V

V_OUT=3.3V

V_IN= 6V

3.305

3.3

V_IN= 12V

V_IN= 16V

1.499

V_IN= 18V

V_IN= 24V

1.2

3.295

0

1.498

0

0.4

0.8

I_OUT(A)

1.6

0.4

0.8

I_OUT(A)

1.2

1.6

2

FIGURE 2-8:

3.3V V_OUTvs. I_OUT.

FIGURE 2-11:

1.5V V_OUTvs. I_OUT.

2.515

2.513

2.511

2.509

2.507

2.505

2.503

2.501

2.499

2.497

2.495

0

0.904

0.903

0.902

0.901

0.9

V_OUT=0.9V

V_OUT=2.5V

V_IN= 6V

V_IN= 12V

V_IN= 8V

0.899

0.898

V_IN= 10V

1.2

V_IN= 24V

V_IN= 18V

1.6

0.897

0

0.4

0.8

I_OUT(A)

1.2

0.4

0.8

1.6

2

I_OUT(A)

FIGURE 2-9:

2.5V V_OUTvs. I_OUT.

FIGURE 2-12:

0.9V V_OUTvs. I_OUT.

DS22285A-page 8

MCP16321/2

Note: Unless otherwise indicated, V_IN= 12V, EN = Floating (Internally pulled up), C_IN= 20 µF, C_OUT= 2x22 µF,

L = 4.7 µH (XAL6060-472MEB), I_LOAD= 200 mA, T_A= +25°C. MCP16321 maximum output current = 1A.

5.02

5.015

5.01

5.005

5

1.804

1.803

1.802

1.801

1.8

V_OUT= 1.8V

V_OUT= 5V

I_OUT= 1A

4.995

4.99

4.985

I_OUT= 2A

1.799

1.798

I_OUT= 2A

6

8

10

12

V_IN(V)

14

16

18

6

8

10 12 14 16 18 20 22 24

V_IN(V)

FIGURE 2-13:

5V V_OUTvs V_IN.

FIGURE 2-16:

1.8V V_OUTvs V_IN.

1.503

1.5025

1.502

1.5015

1.501

1.5005

1.5

3.31

3.308

3.306

3.304

3.302

3.3

V_OUT= 3.3V

V_OUT= 1.5V

I_OUT= 2A

I_OUT= 1A

3.298

3.296

3.294

1.4995

1.499

I_OUT= 2A

1.4985

6

8

10

V_OUT(V)

12

14

16

6

8

10 12 14 16 18 20 22 24

V_IN(V)

FIGURE 2-14:

3.3V V_OUTvs V_IN.

FIGURE 2-17:

1.5V V_OUTvs V_IN.

0.9012

0.901

2.506

2.505

2.504

2.503

2.502

2.501

2.5

2.499

2.498

2.497

2.496

6

V_OUT= 2.5V

V_OUT= 0.9V

0.9008

0.9006

0.9004

0.9002

0.9

I_OUT= 1A

0.8998

0.8996

I_OUT= 2A

0.8994

6

8

10 12 14 16 18 20 22 24

V_IN(V)

7

8

9

10

V_IN(V)

FIGURE 2-15:

2.5V V_OUTvs V_IN.

FIGURE 2-18:

0.9V V_OUTvs V_IN.

DS22285A-page 9

MCP16321/2

Note: Unless otherwise indicated, V_IN= 12V, EN = Floating (Internally pulled up), C_IN= 20 µF, C_OUT= 2x22 µF,

L = 4.7 µH (XAL6060-472MEB), I_LOAD= 200 mA, T_A= +25°C. MCP16321 maximum output current = 1A.

8

7

6

5

4

3

2

1

0

1020

1015

1010

1005

1000

995

990

985

980

6

10

14

V_IN(V)

18

22

-40

-10

20

50

80

110

Ambient Temperature (°C)

FIGURE 2-19:

Shutdown Current vs. Input

FIGURE 2-22:

Oscillator Frequency vs.

Voltage.

Temperature (I_OUT= 300 mA).

5.50

5.45

4.90

4.85

4.80

4.75

4.70

4.65

4.60

4.55

4.50

4.45

-40

I_OUT= 0A

5.40

5.35

5.30

5.25

5.20

-10

20

50

80

110

-40

-10

20

50

80

110

Ambient Temperature (°C)

FIGURE 2-20:

Shutdown Current vs.

FIGURE 2-23:

Input Quiescent Current vs.

Temperature.

Temperature (No Load, Switching).

2.42

2.40

3.300

3.298

3.296

3.294

3.292

3.290

3.288

3.286

I_OUT= 0.1A

I_OUT= 0A

2.38

I_OUT= 1A

2.36

2.34

2.32

2.30

2.28

3.284

-40

-10

20

50

80

110

-40

-10

20

50

80

110

Ambient Temperature (°C)

FIGURE 2-21:

Output Voltage vs.

FIGURE 2-24:

Input Current vs.

Temperature.

Temperature (No Load, No Switching).

DS22285A-page 10

MCP16321/2

Note: Unless otherwise indicated, V_IN= 12V, EN = Floating (Internally pulled up), C_IN= 20 µF, C_OUT= 2x22 µF,

L = 4.7 µH (XAL6060-472MEB), I_LOAD= 200 mA, T_A= +25°C. MCP16321 maximum output current = 1A.

V_OUT= 3.3V

_OUT= 200 mA

V_IN= 12V

30

25

20

15

10

5

Typical Mininimum Duty Cycle = 7%

I

0

0.9

1.2

1.5

V_OUT(V)

1.8

2.1

FIGURE 2-25:

Maximum V_INto V_OUTRatio

FIGURE 2-28:

Startup From Enable.

for Continuous Switching.

V_OUT= 3.3V

I_OUT= 50 mA

V_IN= 12V

V_OUT= 3.3V

I_OUT= 200 mA

V_IN= 12V

FIGURE 2-26:

Light Load Switching

FIGURE 2-29:

Startup From V_IN.

Waveforms.

V_OUT= 3.3V

I_OUT= 500 mA

V_IN= 12V

I_OUT= 100 mA to 600 mA

V_IN= 12V

FIGURE 2-27:

Heavy Load Switching

FIGURE 2-30:

Load Transient Response.

Waveforms.

DS22285A-page 11

MCP16321/2

Note: Unless otherwise indicated, V_IN= 12V, EN = Floating (Internally pulled up), C_IN= 20 µF, C_OUT= 2x22 µF,

L = 4.7 µH (XAL6060-472MEB), I_LOAD= 200 mA, T_A= +25°C. MCP16321 maximum output current = 1A.

V_OUT= 3.3V

I_OUT= 200 mA

V_IN= 6V to 10V

FIGURE 2-31:

Line Transient Response.

DS22285A-page 12

MCP16321/2

3.0

PIN DESCRIPTIONS

The descriptions of the pins are listed in Table 3-1.

TABLE 3-1:

PIN FUNCTION TABLE

Symbol

MCP16321/2

3x3 QFN

Description

1

2

3

4

5

SW

V_IN

Output switch node, connects to the inductor and the bootstrap capacitor

Input supply voltage pin for power and internal biasing

Primary signal ground

V_IN

SGND

V_FB

Output voltage feedback pin. Connect V_FBto V_OUTfor fixed version and output

resistor divider for adjustable version.

6

7

8

9

NC

PG

EN

No Connection

Power Good open-drain output, pulled up to a maximum of 6V

Enable input pin. Logic high enables the operation. Internally pulled up, pull EN pin

low to disable regulator’s output. Maximum voltage on EN input is 6V.

10

BOOST

Boost voltage that drives the internal NMOS control switch. A bootstrap capacitor

is connected between the BOOST and SW pins.

11

12

13

14

15

16

17

V_IN

SW

Input supply voltage pin for power and internal biasing

Output switch node, connects to the inductor and the bootstrap capacitor

GND supply for the internal low-side NMOS/integrated diode

Output switch node, connects to the inductor and the bootstrap capacitor

Exposed Thermal Pad (EP); must be connected to GND

SW

PGND

SW

EP

3.1

Switch Pin (SW)

3.3

Signal Ground Pin (S

)

GND

The drain of the low-side N-Channel switch is

connected internally to the source of the high-side

N-Channel switch, and externally to the SW node,

consisting of the inductor and bootstrap capacitor. The

SW node can rise very fast as a result of the internal

high-side switch turning on. It should be connected

directly to the 4.7 µH inductor with a wide, short trace.

This ground is used for the majority of the device,

including the analog reference, control loop, and other

circuits.

3.4

Feedback Voltage Pin (V

)

FB

The V_FBinput pin is used to provide output voltage

regulation by either using a resistor divider or V_OUT

directly. For the adjustable version, the V_FBwill be 0.9V

typical with the output voltage in regulation. For the

fixed version, the V_FBwill be equal to the

corresponding V_OUTvalue.

3.2

Power Supply Input Voltage Pin

(V )

IN

Connect the input voltage source to V_IN. The input

source should be decoupled to GND using 2 x 10 µF

capacitors. The amount of the capacitance depends on

the impedance of the source and output current. The

input capacitors provide AC current for the high-side

power switch and a stable voltage source for the

internal device power. This capacitor should be

connected as close as possible to the V_INand GND

pins.

3.5

Power Good Pin (PG)

PG is an open drain, active low output. The regulator

output voltage is monitored and the PG line will remain

low until the output voltage reaches the V_OUT-UV

threshold. Once the internal comparator detects that

the output voltage is above the V_OUT-UVthreshold, an

internal delay timer is activated. After a 10 ms delay,

the PG open drain output pin can be pulled high,

indicating that the output voltage is in regulation. The

maximum voltage applied to the PG output pin should

not exceed 6V.

DS22285A-page 13

MCP16321/2

3.6

Enable Pin (EN)

The EN input pin is a logic-level input used to enable or

disable the device. A logic high (> 2.2V) will enable the

regulator output, while a logic low (< 0.8V) will ensure

that the regulator is disabled. This pin is internally

pulled up to an internal reference and will be enabled

when V_IN> UVLO, unless the EN pin is pulled low. The

maximum input voltage applied to the EN pin should

not exceed 6V.

3.7

BOOST Pin (BOOST)

This pin will provide the bootstrap voltage required for

driving the upper internal NMOS switch of the buck

regulator. An external ceramic capacitor placed

between the BOOST input pin and the SW pin will

provide the necessary drive voltage for the upper

switch. During steady state operation, the capacitor is

recharged on every low-side, synchronous switching

cycle. If the Switch mode approaches 100% duty cycle

for the high-side MOSFET, the device will automatically

reduce the duty cycle switch to a minimum off time of

240 ns on every 8^thcycle to recharge the boost

capacitor.

3.8

Power Ground Pin (P

)

GND

This is a separate ground connection used for the low-

side synchronous switch to isolate switching noise from

the rest of the device.

3.9

Exposed Thermal Pad (EP)

There is no internal electrical connection between the

Exposed Thermal Pad (EP) and the P_GNDand S_GND

pins. The EP must be connected to GND on the Printed

Circuit Board (PCB).

DS22285A-page 14

MCP16321/2

4.1.4

ENABLE INPUT

4.0

4.1

DETAILED DESCRIPTION

Device Overview

The enable input (EN) is used to disable the device. If

disabled, the device consumes a minimal current from

the input. Once enabled, the internal soft start controls

the output voltage rate of rise, preventing high-inrush

current and output voltage overshoot. The EN is

internally pulled up or enabled; to disable the converter,

it must be pulled low.

The MCP16321/2 is a high-input voltage, step-down

regulator, capable of supplying 1A/2A to a regulated

output voltage from 0.9V to 5V. Internally, the 1 MHz

oscillator provides a fixed frequency, while the Peak

Current Mode Control architecture varies the duty cycle

for output voltage regulation. An internal floating driver

is used to turn the high-side integrated N-Channel

MOSFET on and off. The power for this driver is

derived from an external boost capacitor whose energy

is replenished when the low-side N-Channel MOSFET

is turned on. When the maximum duty cycle

approaches 100%, the boost capacitor is replenished

for 240 ns after every 8 cycles.

4.1.5

SOFT START

The internal reference voltage rate of rise is controlled

during startup, minimizing the output voltage overshoot

and the inrush current.

4.1.6

OUTPUT OVER VOLTAGE

PROTECTION

If the output of the regulator exceeds 103% of the

regulation voltage, the SW outputs will tri-state to

protect the device from damage. This check occurs at

the start of each switching cycle.

4.1.1

INTERNAL REFERENCE VOLTAGE

V_REF

For the adjustable version, an integrated precise 0.9V

reference combined with an external resistor divider

sets the desired converter output voltage. The resistor

divider can vary without affecting the control system

gain. High-value resistors consume less current, but

are more susceptible to noise. For the fixed version, an

integrated precise voltage reference is set to the

4.1.7

INPUT UNDER VOLTAGE LOCKOUT

An integrated Under Voltage Lockout (UVLO) prevents

the converter from starting until the input voltage is high

enough for normal operation. The converter will

typically start at 5.75V (typical) and operate down to

5.25V (typical). Hysteresis of 500 mV (typical) is added

to prevent starting and stopping during startup, as a

result of loading the input voltage source.

desired V_OUTvalue and is directly connected to V_OUT

.

4.1.2 INTERNAL COMPENSATION

All control system components necessary for stable

operation over the entire device operating range are

integrated, including the error amplifier and inductor

current slope compensation.

4.1.8

MINIMUM DUTY CYCLE

A minimum duty cycle of 70 ns typical prevents the

device from constant switching for high step-down

voltage ratios. Duty cycles less than this minimum will

initiate pulse skipping to maintain output voltage

regulation, resulting in higher output voltage ripple.

Duty cycle for continuous inductor current operation is

approximated by V_OUT/V_IN. For a 1 MHz switching

frequency or 1 µs period, this results in a 7% duty cycle

minimum. Maximum V_INfor continuous switching can

be approximated dividing V_OUTby the minimum duty

cycle or 7%. For example, the maximum input voltage

for continuous switching for a 1.5V output is equal to

approximately 21V.

4.1.3

EXTERNAL COMPONENTS

External components consist of:

• Input capacitor

• Output filter (inductor and capacitor)

• Boost capacitor

• Resistor divider (adjustable version only)

The selection of the external inductor, output capacitor,

input capacitor and boost capacitor is dependent upon

the output voltage and the maximum output current.

DS22285A-page 15

MCP16321/2

4.1.9

OVERTEMPERATURE

PROTECTION

Overtemperature protection limits the silicon die

temperature to +170°C by turning the converter off. The

normal switching resumes at +160°C.

V_IN

C_IN

UV

Protection

V_OUT

EN

OTEMP

Protection

Monitor and

Control

BOOST

Voltage

4.2V

PG

Current

Limit

V_OUT

R_TOP

Slope

Comp

BOOST

OV

Protection

FB

+

CS

R_BOT

C_BOOST

V_REFand

Softstart

+

COMP

HS

Drive

Amp

-

PWM

Comparator

L

V_OUT

SW

Gate Drive

Control

Internal Bias

Compensation

1 MHz

Oscillator

LS

C_OUT

Drive

-

COMP

+

V_REF

PFM

Comparator

SGND

PGND

FIGURE 4-1:

MCP16321/2 Block Diagram.

DS22285A-page 16

MCP16321/2

4.2

Functional Description

L

V_OUT

4.2.1

STEP-DOWN OR BUCK

CONVERTER

S₁

I_L

The MCP16321/2 is a synchronous, step-down or buck

converter capable of stepping input voltages ranging

from 6V to 24V down to 0.9V to 5V.

C_OUT

V_IN

S₂

The integrated high-side switch is used to chop or

modulate the input voltage using a controlled duty cycle

for output voltage regulation. The integrated low-side

switch is used to freewheel current when the high-side

switch is turned off. High efficiency is achieved by using

low-resistance switches and low equivalent series

resistance (ESR), inductor and capacitors. When the

high-side switch is turned on, a DC voltage is applied to

the inductor (V_IN– V_OUT), resulting in a positive linear

ramp of inductor current. When the high-side switch

turns off and the low-side switch turns on, the applied

inductor voltage is equal to –V_OUT, resulting in a

negative linear ramp of inductor current. In order to

ensure there is no shoot-through current, a dead time

where both switches are off is implemented between

the high-side switch turning off and the low-side switch

turning on, and the low-side switch turning off and the

high-side switch turning on.

I_L

I_OUT

V_IN

SW

V_OUT

S₁ON

S₂ON

Continuous Inductor Current Mode

For steady-state, continuous inductor current

operation, the positive inductor current ramp must

equal the negative current ramp in magnitude. While

operating in steady state, the switch duty cycle must be

equal to the relationship of V_OUT/V_INfor constant

output voltage regulation, under the condition that the

inductor current is continuous, or never reaches zero.

For discontinuous inductor current operation, the

steady-state duty cycle will be less than V_OUT/V_INto

maintain voltage regulation. When the inductor current

reaches zero, the low-side switch is turned off so that

current does not flow in the reverse direction, keeping

the efficiency high. The average of the chopped input

voltage or SW node voltage is equal to the output

voltage, while the average inductor current is equal to

the output current.

I_L

I_OUT

V_IN

SW

S₂Both

ON OFF

S₁ON

Discontinuous Inductor Current Mode

FIGURE 4-2:

Converter.

Synchronous Step-Down

DS22285A-page 17

MCP16321/2

4.2.2

PEAK CURRENT MODE CONTROL

4.2.4

HIGH-SIDE DRIVE

The MCP16321/2 integrates a Peak Current Mode

Control architecture, resulting in superior AC regulation

while minimizing the number of voltage loop

compensation components, and their size, for

integration. Peak Current Mode Control takes a small

portion of the inductor current, replicates it and

compares this replicated current sense signal with the

output of the integrated error voltage. In practice, the

inductor current and the internal switch current are

equal during the switch-on time. By adding this peak

current sense to the system control, the step-down

power train system can be approximated by a 1^storder

system rather than a 2^ndorder system. This reduces

the system complexity and increases its dynamic

performance.

The MCP16321/2 features an integrated high-side

N-Channel MOSFET for high efficiency step-down

power conversion. An N-Channel MOSFET is used for

its low resistance and size (instead of a P-Channel

MOSFET). The N-Channel MOSFET gate must be

driven above its source to fully turn on the device,

resulting in a gate-drive voltage above the input to turn

on the high-side N-Channel. The high-side N-Channel

source is connected to the inductor and boost cap or

switch node. When the high-side switch is off and the

low-side is on, the inductor current flows through the

low-side switch, providing a path to recharge the boost

cap from the boost voltage source. An internal boost-

blocking diode is used to prevent current flow from the

boost cap back into the output during the internal

switch-on time. Prior to startup, the boost cap has no

stored charge to drive the switch. An internal regulator

is used to “pre-charge” the boost cap. Once pre-

charged, the switch is turned on and the inductor

current flows. When the high-side switch turns off and

the low-side turns on, current freewheels through the

inductor and low-side switch, providing a path to

recharge the boost cap. When the duty cycle

approaches its maximum value, there is very little time

for the boost cap to be recharged due to the short

amount time that the low-side switch is on. Therefore,

when the maximum duty cycle approaches, the switch

node is forced off for 240 ns every 8 cycles to ensure

that the boost cap gets replenished.

For Pulse-Width Modulation (PWM) duty cycles that

exceed 50%, the control system can become bimodal,

where a wide pulse followed by a short pulse repeats

instead of the desired fixed pulse width. To prevent this

mode of operation, an internal compensating ramp is

summed into the current sense signal.

4.2.3

PULSE WIDTH MODULATION

(PWM)

The internal oscillator periodically starts the switching

period, which in the MCP16321/2’s case occurs every

1 µs or 1 MHz. With the high-side integrated

N-Channel MOSFET turned on, the inductor current

ramps up until the sum of the current sense and slope

compensation ramp exceeds the integrated error

amplifier output. Once this occurs, the high-side switch

turns off and the low-side switch turns on. The error

amplifier output slews up or down to increase or

decrease the inductor peak current feeding into the

output LC filter. If the regulated output voltage is lower

than its target, the inverting error amplifier output rises.

This results in an increase in the inductor current to

correct for errors in the output voltage. The fixed

frequency duty cycle is terminated when the sensed

inductor peak current, summed with the internal slope

compensation, exceeds the output voltage of the error

amplifier. The PWM latch is set by turning off the high-

side internal switch and preventing it from turning on

until the beginning of the next cycle.

DS22285A-page 18

MCP16321/2

5.0.3

GENERAL DESIGN EQUATIONS

5.0

APPLICATION INFORMATION

The step-down converter duty cycle can be estimated

using Equation 5-2 while operating in Continuous

Inductor Current Mode. This equation accounts for the

forward drop of two internal N-Channel MOSFETS. As

load current increases, the voltage drop in both internal

switches will increase, requiring a larger PWM duty

cycle to maintain the output voltage regulation. Switch

voltage drop is estimated by multiplying the switch

5.0.1

TYPICAL APPLICATIONS

The MCP16321/2 synchronous step-down converter

operates over a wide input range, up to 24V maximum.

Typical applications include generating a bias or V_DD

voltage for PIC^®microcontrollers, digital control system

bias supply for AC-DC converters and 12V industrial

input and similar applications.

current times the switch resistance or R_DSON

.

5.0.2

ADJUSTABLE OUTPUT VOLTAGE

CALCULATIONS

EQUATION 5-2:

CONTINUOUS INDUCTOR

CURRENT DUTY CYCLE

To calculate the resistor divider values for the

MCP16321/2 adjustable version, use Equation 5-1.

R_TOPis connected to V_OUT, R_BOTis connected to

SGND, and both are connected to the V_FBinput pin.

V_OUT+ (I_LSW× R_DSONL

D = ------------------------------------------------------------

_IN– (I_HSW× R_DSONH

)

V

5.0.4

INPUT CAPACITOR SELECTION

EQUATION 5-1:

RESISTOR DIVIDER

CALCULATION

The step-down converter input capacitor must filter the

high-input ripple current, as a result of pulsing or

chopping the input voltage. The MCP16321/2 input

voltage pin is used to supply voltage for the power train

and as a source for internal bias. A low equivalent

R_TOP

⎛

⎞

⎠

V_OUT= V_FB× 1 +------------

⎝

R_BOT

series resistance (ESR), preferably

capacitor, is recommended. The

a

ceramic

necessary

EXAMPLE 5-1:

2.0V RESISTOR DIVIDER

capacitance is dependent upon the maximum load

current and source impedance. Three capacitor

parameters to keep in mind are the voltage rating,

equivalent series resistance and the temperature

rating. For wide temperature range applications, a

multilayer X7R dielectric is recommended, while for

V_OUT= 2.0V

V_FB= 0.9V

R_BOT= 10 kΩ

R_TOP= 12.2 kΩ (standard value = 12.3 kΩ)

V_OUT= 2.007V (using standard values)

applications with limited temperature range,

a

multilayer X5R dielectric is acceptable. The input

capacitor voltage rating must be V_INplus margin.

EXAMPLE 5-2:

4.2V RESISTOR DIVIDER

V_OUT= 4.2V

V_FB= 0.9V

5.0.5

OUTPUT CAPACITOR SELECTION

The output capacitor provides a stable output voltage

during sudden load transients, and reduces the output

voltage ripple. As with the input capacitor, X5R and

X7R ceramic capacitors are well suited for this applica-

tion.

R_BOT= 10 kΩ

R_TOP= 36.7 kΩ (standard value = 36.5 kΩ)

V_OUT= 4.185V (using standard values)

The error amplifier is internally compensated to ensure

loop stability. External resistor dividers, inductance and

output capacitance, all have an impact on the control

system and should be selected carefully and evaluated

for stability. A 10 kΩ resistor is recommended as a

good trade-off for quiescent current and noise

immunity.

The MCP16321/2 is internally compensated, so the

output capacitance range is limited. See TABLE 5-1:

“Capacitor Value Range” for the recommended out-

put capacitor range.

The amount and type of output capacitance and

equivalent series resistance will have a significant

effect on the output ripple voltage and system stability.

The range of the output capacitance is limited due to

the integrated compensation of the MCP16321/2.

The output voltage capacitor rating should be a

minimum of V_OUTplus margin.

TABLE 5-1:

Parameter

C_IN

CAPACITOR VALUE RANGE

Min

Max

8 µF

None

DS22285A-page 19

MCP16321/2

TABLE 5-1:

Parameter

C_OUT

CAPACITOR VALUE RANGE

TABLE 5-2:

MCP16321 RECOMMENDED

INDUCTORS

Min

Max

33 µF

None

Size

Part

Number

Value DCR

I_SAT

(A)

WxLxH

(mm)

(µH)

(Ω)

5.0.6

INDUCTOR SELECTION

Coilcraft^®

1008PS

The MCP16321/2 is designed to be used with small

surface mount inductors. Several specifications should

be considered prior to selecting an inductor. To

optimize system performance, low ESR inductors

should be used.

4.7

0.35

0.175

0.125

0.15

1.7 3.81x3.78x2.74

LPS4012

LPS4018

LPS5015

MSS5121

LPS5030

MSS6122

MOS6020

1.8

1.9

1.8

4.1x4.1x1.2

4.1x4.1x1.8

5x5x1.5

EQUATION 5-3:

INDUCTOR CURRENT

RIPPLE

0.095 1.66

0.083

0.065 1.82

5.1x5.1x2.2

5x5x3

2

V_L

6.1x6.1x2.2

6.8x6x2.4

ΔI_L= ----- × t_ON

0.05

1.94

L

Wurth Elektronik^®

744042

4.7

0.07

1.65

4.8x4.8x1.8

8x8x1.1

EXAMPLE 5-3:

MCP16321 PEAK

INDUCTOR CURRENT – 1A

744068

0.072 1.55

0.0545 4.2

7448944

EPCOS^®

LTF5022T

VLC5020T

VLC6020T

8x8x3.8

V_IN= 12V

V_OUT= 3.3V

I_OUT= 1A

4.7

0.073

0.097

0.079

0.122

0.12

2

5.2x5x2.2

5x5x2

2

L = 4.7 µH

1.8

1.7

6x6x2

VLCF5020T 4.7

5x5x2

ΔI

L

I

= --------- + I

VLF5014ST

4.7

4.8x4.6x1.4

LPK

OUT

2

Inductor ripple current = 509 mA

Inductor peak current = 1.255A

TABLE 5-3:

MCP16322 RECOMMENDED

INDUCTORS

An inductor saturation rating minimum of 1.255A is

recommended. A trade-off between size, cost and

efficiency is made to achieve the desired results.

Size

Value DCR I_SAT

WxLxH

Part Number

(µH)

(Ω)

(A)

(mm)

Coilcraft^®

EXAMPLE 5-4:

MCP16322 PEAK

INDUCTOR CURRENT – 2A

MSS6132-472

LPS6225-472

MSS7341-502

4.7

0.056 2.84

0.065 3.2

0.024 3.16

6.1x6.1x3.2

6.2x6.2x2.5

7.3x7.3x4.1

8.89x6.1x5.0

V_IN= 12V

V_OUT= 3.3V

I_OUT= 2A

DO1813H-472 4.7

Wurth Elektronik^®

0.054

2.6

L = 4.7 µH

7447785004

7447786004

7447789004

EPCOS^®

4.7

0.06

0.057

0.033

2.5

2.8

3.9

5.9x6.2x3.3

5.9x6.2x5.1

7.3x3.2x1.5

ΔI

L

I

= --------- + I

LPK

OUT

2

Inductor ripple current = 509 mA

Inductor peak current = 2.255A

B82464G2

B82464A2

4.7

0.033

0.03

3.1 10.4x10.4x3.0

4.5 10.4x10.4x3.0

An inductor saturation rating minimum of 2.255A is

recommended. A trade-off between size, cost and

efficiency is made to achieve the desired results.

DS22285A-page 20

MCP16321/2

5.0.7

BOOST CAPACITOR

EXAMPLE 5-5:

POWER DISSIPATION –

MCP16321

The boost capacitor is used to supply current for the

internal high-side drive circuitry that is above the input

voltage. The boost capacitor must store enough energy

to completely drive the high-side switch on and off. A

22 nF X5R or X7R capacitor is recommended for all

applications. The boost capacitor maximum voltage is

V_IN

V_OUT

I_OUT

=

12V

5.0V

1A

Efficiency

92.5%

405 mW

0.04 Ω

40 mW

5.5V, so

recommended.

a

6.3V or 10V rated capacitor is

Total System Dissipation

L_ESR

P_L

5.0.8

THERMAL CALCULATIONS

The MCP16321/2 is available in a 3x3 QFN-16

package. By calculating the power dissipation and

applying the package thermal resistance (θ_JA), the

junction temperature is estimated. The maximum

continuous junction temperature rating for the

MCP16321/2 is +125°C.

MCP16321 internal power dissipation estimate:

P_DIS– P_L

θ_JA

=

365 mW

38.5°C/W

+14.052°C

Estimated Junction

Note 1:

θ_JA= 38.5°C/W for a 4-layer FR4 Printed

Circuit Board with a 13.5 in², 1 oz internal

copper ground plane.

To quickly estimate the internal power dissipation for

the switching step-down regulator, an empirical

calculation using measured efficiency can be used.

Given the measured efficiency, the internal power

dissipation is estimated in Equation 5-4. This power

dissipation includes all internal and external

component losses. For a quick internal estimate,

subtract the estimated inductor ESR loss from the P_DIS

calculation in Equation 5-4.

2: A smaller ground plane will result in a

larger θ_JAtemperature rise.

EXAMPLE 5-6:

POWER DISSIPATION –

MCP16322

V_IN

=

12V

V_OUT

3.3V

EQUATION 5-4:

TOTAL POWER

I_OUT

2A

DISSIPATION ESTIMATE

Efficiency

87.5%

943 mW

0.04 Ω

160 mW

V_OUT× I_OUT

P_DIS= ------------------------------ – (V_OUT× I_OUT

Efficency

Total System Dissipation

)

L_ESR

P_L

The difference between the first term, input power, and

the second term, power delivered, is the total system

power dissipation. The inductor losses are estimated

MCP16322 internal power dissipation estimate:

P_DIS– P_L

θ_JA

=

783 mW

38.5°C/W

+30.14°C

by P_L= I_OUT²x L_ESR

.

Estimated Junction

DS22285A-page 21

MCP16321/2

frequency switch current, C_INalso provides a stable

voltage source for the internal MCP16321/2 circuitry.

Unstable PWM operation can result if there are

excessive transients or ringing on the V_INpin of the

MCP16321/2 device. In Figure 5-1, C_INis placed close

to the V_INpins. A ground plane on the bottom of the

board provides a low resistive and low inductive path

for the return current. The next priority in placement is

the freewheeling current loop formed by C_OUTand L

while strategically placing the C_OUTreturn close to C_IN

return. Next, C_BOOSTshould be placed between the

boost pin and the switch node pin. This leaves space

close to the MCP16321/2 V_FBpin to place R_TOPand

R_BOT. R_TOPand R_BOTare routed away from the switch

node so noise is not coupled into the high-impedance

V_FBinput.

5.0.9

PCB LAYOUT INFORMATION

Good printed circuit board layout techniques are

important to any switching circuitry, and switching

power supplies are no different. When wiring the

switching high-current paths, short and wide traces

should be used. Therefore, it is important that the input

and output capacitors be placed as close as possible to

the MCP16321/2 to minimize the loop area.

The feedback resistors and feedback signal should be

routed away from the switching node and the switching

current loop. When possible, ground planes and traces

should be used to help shield the feedback signal and

minimize noise and magnetic interference.

A good MCP16321/2 layout starts with C_INplacement.

C_INsupplies current to the input of the circuit when the

switch is turned on. In addition to supplying high-

Bottom layer is ground plane

V_OUT

L

C_OUT

R_{PG 10Ω}

C_BOOST

GND

MCP16321/2

R

_BOTR_TOP

Trace on

bottom layer

C_IN

V_IN

GND

FIGURE 5-1:

Recommended Layout.

DS22285A-page 22

MCP16321/2

C_BOOST

V_OUT

0.9V to 5V

L

BOOST

V_IN

SW

6.0V to 24V

V_IN

EN

10Ω

R_TOP

C_OUT

V_FB

V_OUT

R_PG

R_BOT

C_IN

PG

S_GND

P_GND

FIGURE 5-2:

TABLE 5-4:

Recommended Layout – Schematic.

RECOMMENDED LAYOUT

COMPONENTS

Component

C_IN

Value

2 x 10 µF

2 x 22 µF

4.7 µH

36.5 kΩ

10 kΩ

C_OUT

L

R_TOP

R_BOT

R_PG

10 kΩ

C_BOOST

22 nF

DS22285A-page 23

MCP16321/2

NOTES:

DS22285A-page 24

MCP16321/2

6.0

6.1

PACKAGING INFORMATION

Package Marking Information

16-Lead QFN (3x3x0.9 mm)

Example

Part Number

Code

MCP16321T-150E/NG

MCP16321T-180E/NG

MCP16321T-250E/NG

MCP16321T-330E/NG

MCP16321T-500E/NG

MCP16321T-ADJE/NG

MCP16322T-150E/NG

MCP16322T-180E/NG

MCP16322T-250E/NG

MCP16322T-330E/NG

MCP16322T-500E/NG

MCP16322T-ADJE/NG

AAA

AAB

AAC

AAD

AAE

AAF

ABA

ABB

ABC

ABD

ABE

ABF

AAA

E114

5256

Legend: XX...X Customer-specific information

Y

Year code (last digit of calendar year)

YY

Year code (last 2 digits of calendar year)

WW

NNN

Week code (week of January 1 is week ‘01’)

Alphanumeric traceability code

e

3

Pb-free JEDEC designator for Matte Tin (Sn)

This package is Pb-free. The Pb-free JEDEC designator (

can be found on the outer packaging for this package.

*

)

3

e

Note: In the event the full Microchip part number cannot be marked on one line, it will

be carried over to the next line, thus limiting the number of available

characters for customer-specific information.

DS22285A-page 25

MCP16321/2

DS22285A-page 26

MCP16321/2

DS22285A-page 27

MCP16321/2

DS22285A-page 28

MCP16321/2

APPENDIX A: REVISION HISTORY

Revision A (December 2011)

• Original Release of this Document.

DS22285A-page 29

MCP16321/2

NOTES:

DS22285A-page 30

MCP16321/2

PRODUCT IDENTIFICATION SYSTEM

To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.

PART NO.

Device

T

X

/XX

-XXX

Examples:

a) MCP16321T-150E/NG:

Tape and Reel,

Tape and Reel

Temperature Package

Range

Output

Voltage

1.5V Output Voltage,

Extended Temperature

16LD QFN Package

b) MCP16321T-ADJE/NG: Tape and Reel,

Adjustable Output Voltage,

Device:

MCP16321T:

MCP16322T:

High-Efficiency Synchronous Buck

Regulator (Tape and Reel) (QFN)

High-Efficiency Synchronous Buck

Regulator (Tape and Reel) (QFN)

Extended Temperature

16LD QFN Package

Tape and Reel,

c) MCP16322T-150E/NG:

1.5V Output Voltage,

Extended Temperature

16LD QFN Package

Output Voltage

150

180

250

330

500

ADJ

=

1.5V

1.8V

2.5V

3.3V

5.0V

d) MCP16322T-ADJE/NG: Tape and Reel,

Adjustable Output Voltage,

Extended Temperature

16LD QFN Package

Adjustable

Temperature Range:

Package:

E

= -40°C to +125°C

NG = Plastic Quad Flat, No Lead Package

(3x3x0.9 mm Body) (QFN), 16-lead

DS22285A-page 31

MCP16321/2

NOTES:

DS22285A-page 32

Note the following details of the code protection feature on Microchip devices:

•

Microchip products meet the specification contained in their particular Microchip Data Sheet.

•

Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the

intended manner and under normal conditions.

•

There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our

knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data

Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

•

Microchip is willing to work with the customer who is concerned about the integrity of their code.

Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not

mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our

products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Information contained in this publication regarding device

applications and the like is provided only for your convenience

and may be superseded by updates. It is your responsibility to

ensure that your application meets with your specifications.

MICROCHIP MAKES NO REPRESENTATIONS OR

WARRANTIES OF ANY KIND WHETHER EXPRESS OR

IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION,

INCLUDING BUT NOT LIMITED TO ITS CONDITION,

QUALITY, PERFORMANCE, MERCHANTABILITY OR

FITNESS FOR PURPOSE. Microchip disclaims all liability

arising from this information and its use. Use of Microchip

devices in life support and/or safety applications is entirely at

the buyer’s risk, and the buyer agrees to defend, indemnify and

hold harmless Microchip from any and all damages, claims,

suits, or expenses resulting from such use. No licenses are

conveyed, implicitly or otherwise, under any Microchip

intellectual property rights.

Trademarks

The Microchip name and logo, the Microchip logo, dsPIC,

KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART,

32

PIC logo, rfPIC and UNI/O are registered trademarks of

Microchip Technology Incorporated in the U.S.A. and other

countries.

FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,

MXDEV, MXLAB, SEEVAL and The Embedded Control

Solutions Company are registered trademarks of Microchip

Technology Incorporated in the U.S.A.

Analog-for-the-Digital Age, Application Maestro, chipKIT,

chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net,

dsPICworks, dsSPEAK, ECAN, ECONOMONITOR,

FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP,

Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB,

MPLINK, mTouch, Omniscient Code Generation, PICC,

PICC-18, PICDEM, PICDEM.net, PICkit, PICtail, REAL ICE,

rfLAB, Select Mode, Total Endurance, TSHARC,

UniWinDriver, WiperLock and ZENA are trademarks of

Microchip Technology Incorporated in the U.S.A. and other

countries.

SQTP is a service mark of Microchip Technology Incorporated

in the U.S.A.

All other trademarks mentioned herein are property of their

respective companies.

Printed on recycled paper.

ISBN: 978-1-61341-865-9

Microchip received ISO/TS-16949:2009 certification for its worldwide

headquarters, design and wafer fabrication facilities in Chandler and

Tempe, Arizona; Gresham, Oregon and design centers in California

and India. The Company’s quality system processes and procedures

are for its PIC^®MCUs and dsPIC^®DSCs, KEELOQ^®code hopping

devices, Serial EEPROMs, microperipherals, nonvolatile memory and

analog products. In addition, Microchip’s quality system for the design

and manufacture of development systems is ISO 9001:2000 certified.

DS22285A-page 33

Worldwide Sales and Service

AMERICAS

ASIA/PACIFIC

EUROPE

Corporate Office

2355 West Chandler Blvd.

Chandler, AZ 85224-6199

Tel: 480-792-7200

Fax: 480-792-7277

Technical Support:

http://www.microchip.com/

support

Asia Pacific Office

Suites 3707-14, 37th Floor

Tower 6, The Gateway

Harbour City, Kowloon

Hong Kong

Tel: 852-2401-1200

Fax: 852-2401-3431

India - Bangalore

Tel: 91-80-3090-4444

Fax: 91-80-3090-4123

Austria - Wels

Tel: 43-7242-2244-39

Fax: 43-7242-2244-393

Denmark - Copenhagen

Tel: 45-4450-2828

Fax: 45-4485-2829

India - New Delhi

Tel: 91-11-4160-8631

Fax: 91-11-4160-8632

France - Paris

Tel: 33-1-69-53-63-20

Fax: 33-1-69-30-90-79

India - Pune

Tel: 91-20-2566-1512

Fax: 91-20-2566-1513

Australia - Sydney

Tel: 61-2-9868-6733

Fax: 61-2-9868-6755

Web Address:

www.microchip.com

Germany - Munich

Tel: 49-89-627-144-0

Fax: 49-89-627-144-44

Japan - Osaka

Tel: 81-66-152-7160

Fax: 81-66-152-9310

Atlanta

Duluth, GA

Tel: 678-957-9614

Fax: 678-957-1455

China - Beijing

Tel: 86-10-8569-7000

Fax: 86-10-8528-2104

Italy - Milan

Tel: 39-0331-742611

Fax: 39-0331-466781

Japan - Yokohama

Tel: 81-45-471- 6166

Fax: 81-45-471-6122

China - Chengdu

Tel: 86-28-8665-5511

Fax: 86-28-8665-7889

Boston

Westborough, MA

Tel: 774-760-0087

Fax: 774-760-0088

Netherlands - Drunen

Tel: 31-416-690399

Fax: 31-416-690340

Korea - Daegu

Tel: 82-53-744-4301

Fax: 82-53-744-4302

China - Chongqing

Tel: 86-23-8980-9588

Fax: 86-23-8980-9500

Chicago

Itasca, IL

Tel: 630-285-0071

Fax: 630-285-0075

Spain - Madrid

Tel: 34-91-708-08-90

Fax: 34-91-708-08-91

Korea - Seoul

China - Hangzhou

Tel: 86-571-2819-3187

Fax: 86-571-2819-3189

Tel: 82-2-554-7200

Fax: 82-2-558-5932 or

82-2-558-5934

UK - Wokingham

Tel: 44-118-921-5869

Fax: 44-118-921-5820

Cleveland

Independence, OH

Tel: 216-447-0464

Fax: 216-447-0643

China - Hong Kong SAR

Tel: 852-2401-1200

Fax: 852-2401-3431

Malaysia - Kuala Lumpur

Tel: 60-3-6201-9857

Fax: 60-3-6201-9859

Dallas

Addison, TX

Tel: 972-818-7423

Fax: 972-818-2924

China - Nanjing

Tel: 86-25-8473-2460

Fax: 86-25-8473-2470

Malaysia - Penang

Tel: 60-4-227-8870

Fax: 60-4-227-4068

China - Qingdao

Tel: 86-532-8502-7355

Fax: 86-532-8502-7205

Philippines - Manila

Tel: 63-2-634-9065

Fax: 63-2-634-9069

Detroit

Farmington Hills, MI

Tel: 248-538-2250

Fax: 248-538-2260

China - Shanghai

Tel: 86-21-5407-5533

Fax: 86-21-5407-5066

Singapore

Tel: 65-6334-8870

Fax: 65-6334-8850

Indianapolis

Noblesville, IN

Tel: 317-773-8323

Fax: 317-773-5453

China - Shenyang

Tel: 86-24-2334-2829

Fax: 86-24-2334-2393

Taiwan - Hsin Chu

Tel: 886-3-5778-366

Fax: 886-3-5770-955

Los Angeles

China - Shenzhen

Tel: 86-755-8203-2660

Fax: 86-755-8203-1760

Taiwan - Kaohsiung

Tel: 886-7-536-4818

Fax: 886-7-330-9305

Mission Viejo, CA

Tel: 949-462-9523

Fax: 949-462-9608

China - Wuhan

Tel: 86-27-5980-5300

Fax: 86-27-5980-5118

Taiwan - Taipei

Tel: 886-2-2500-6610

Fax: 886-2-2508-0102

Santa Clara

Santa Clara, CA

Tel: 408-961-6444

Fax: 408-961-6445

China - Xian

Tel: 86-29-8833-7252

Fax: 86-29-8833-7256

Thailand - Bangkok

Tel: 66-2-694-1351

Fax: 66-2-694-1350

Toronto

Mississauga, Ontario,

Canada

China - Xiamen

Tel: 905-673-0699

Fax: 905-673-6509

Tel: 86-592-2388138

Fax: 86-592-2388130

China - Zhuhai

Tel: 86-756-3210040

Fax: 86-756-3210049

11/29/11

DS22285A-page 34


型号：	MCP16321T-250E
厂家：	MICROCHIP
描述：	24V Input, 1A/2A Output, High Efficiency Synchronous Buck Regulator with Power Good Indication 24V输入， 1A / 2A输出，高效率同步降压型稳压器具有电源状态良好指示稳压器
文件：	总34页 (文件大小：1064K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

MCP16321T-250E [MICROCHIP]

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