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MCP16323

Features

• Up to 95% Typical Efficiency

• Input Voltage Range: 6.0V to 18V

• 3A Output Current

• 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

• Low Device Shutdown Current

• Peak Current Mode Control

• Internal Compensation

• Stable with Ceramic Capacitors

• Internal Soft-Start

• Cycle-by-Cycle Peak Current Limit

• Under Voltage Lockout (UVLO): 5.75V

• Overtemperature Protection

•V

OUT

Overvoltage Protection

•V

OUT

Voltage Supervisor Reported at the PG Pin

• Available Package: QFN-16 (3x3 mm)

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

•Consumer

• Medical and Health Care

• Distributed Power Supplies

Description

The MCP16323 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 18V. Integrated features include a

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

frequency Peak Current Mode Control, internal

compensation, peak current limit, V

OUT

overvoltage

protection and overtemperature protection. Minimal

external components are necessary to develop a

complete synchronous step-down DC-DC converter

power supply.

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.

The MCP16323 device can supply 3A 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.

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

signal applied to the EN input. The EN pin 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.

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

MCP16323 is offered in a 3x3 QFN-16 surface mount

package.

18V Input, 3A Output, High Efficiency Synchronous Buck Regulator

with Power Good Indication

Summary of content (32 pages)

PAGE 1
MCP16323 18V Input, 3A Output, High Efficiency Synchronous Buck Regulator with Power Good Indication Features Description • • • • The MCP16323 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 18V.
PAGE 2
MCP16323 Package Type SW PGND PGND SW MCP16323 3x3 QFN* 16 15 14 13 12 SW SW 1 VIN 2 11 VIN EP 17 VIN 3 10 BOOST 9 EN 5 6 7 8 FB NC NC PG SGND 4 * Includes Exposed Thermal Pad (EP); see Table 3-1. Typical Applications Typical Application with Adjustable Output Voltage CBOOST 22 nF L1 4.7 µH BOOST VIN 6.0V to 18V SW VIN 36.5 kΩ MCP16323 CIN 2x10 µF VOUT 4.
PAGE 3
MCP16323 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings† VIN ....................................................................... -0.3V to 20V SW ......................................................................... -1V to 20V BOOST – GND ........................................... -0.3V to (VIN+6V) † Notice: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
PAGE 4
MCP16323 DC CHARACTERISTICS (CONTINUED) Electrical Characteristics: Unless otherwise indicated, TA = +25°C, VIN = 12V, VOUT = 3.3V, IOUT = 300 mA, L = 4.7 µH, COUT = 2x22 µF, CIN = 2x10 µF. Boldface specifications apply over the TJ range of -40°C to +125°C. Parameters Sym Min Typ Max Units VFB-PFM — VOUT + 1% — V IFB — 100 — nA VIH 2.2 — — V EN Input Logic Low VIL — — 0.8 V EN Input Hysteresis VEN-HYST — 480 — mV IENLK — 3.5 — µA VEN = 5V — -1.
PAGE 5
MCP16323 TABLE 1-1: TEMPERATURE CHARACTERISTICS Electrical Characteristics Parameters Sym Min Typ Max Units Operating Junction Temperature Range TJ -40 — 125 °C Storage Temperature Range TA -65 — 150 °C Maximum Junction Temperature TJ — — 150 °C θJA — 38.5 — Conditions Temperature Ranges Steady State Transient Package Thermal Resistances Thermal Resistance, 16L 3x3-QFN Note 1: °C/W 2 Measured using a 4-layer FR4 Printed Circuit Board with a 13.
PAGE 7
MCP16323 2.0 TYPICAL PERFORMANCE CURVES 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.
PAGE 8
MCP16323 Note: Unless otherwise indicated, VIN = 12V, EN = Floating (internally pulled up), CIN = 20 µF, COUT = 2x22 µF, L = 4.7 µH, ILOAD = 200 mA, TA = +25°C. 5.1 1.812 VIN = 12V 5.05 1.808 VIN = 18V 4.95 VOUT (V) VOUT (V) 5 4.9 VIN = 6V VOUT = 5V 4.85 1.804 1.802 VIN = 12V 1.8 4.75 1.798 0.6 FIGURE 2-7: 1.2 1.8 IOUT (A) 2.4 3 5V VOUT vs. IOUT. 3.33 VOUT (V) 3.325 VIN = 6V 3.315 3.31 VIN = 18V 3.305 3.3 VIN = 12V 3.295 0 0.6 FIGURE 2-8: 1.2 1.8 IOUT (A) 2.4 0.
PAGE 9
MCP16323 Note: Unless otherwise indicated, VIN = 12V, EN = Floating (internally pulled up), CIN = 20 µF, COUT = 2x22 µF, L = 4.7 µH, ILOAD = 200 mA, TA = +25°C. 5.04 1.804 1.803 IOUT = 1A IOUT = 2A 4.98 VOUT (V) 5 VOUT (V) VOUT = 1.8V VOUT = 5V 5.02 IOUT = 3A 4.96 1.8 4.92 1.799 IOUT = 3A IOUT = 1A 6 8 FIGURE 2-13: 10 12 VIN (V) 14 16 1.798 18 5V VOUT vs. VIN. 6 10 12 VIN (V) 14 16 18 1.8V VOUT vs. VIN. 1.503 VOUT = 3.3V 3.308 8 FIGURE 2-16: 3.31 VOUT = 1.5V 1.
PAGE 10
MCP16323 Note: Unless otherwise indicated, VIN = 12V, EN = Floating (internally pulled up), CIN = 20 µF, COUT = 2x22 µF, L = 4.7 µH, ILOAD = 200 mA, TA = +25°C. 1020 Oscillator Frequency (kHz) 8 Shudown Current (µA) 7 6 5 4 3 2 1 0 9 12 VIN (V) 15 1005 1000 995 990 985 18 Shutdown Current vs. Input -40 4.90 4.85 4.80 4.75 4.70 4.65 4.60 4.55 4.50 4.45 -40 -10 FIGURE 2-20: Temperature. 20 50 80 Ambient Temperature (°C) IOUT = 0.1A 3.298 3.296 IOUT = 1A 3.294 3.292 3.290 3.288 3.286 3.
PAGE 11
MCP16323 Note: Unless otherwise indicated, VIN = 12V, EN = Floating (internally pulled up), CIN = 20 µF, COUT = 2x22 µF, L = 4.7 µH, ILOAD = 200 mA, TA = +25°C. VOUT = 3.3V IOUT = 200 mA VIN = 12V 30 Typical Minimum Duty Cycle = 7% Max VIN (V) 25 20 15 10 5 0 0.9 1.2 1.5 VOUT (V) 1.8 2.1 FIGURE 2-25: Maximum VIN to VOUT Ratio for Continuous Switching. VOUT = 3.3V IOUT = 50 mA VIN = 12V FIGURE 2-26: Waveforms. Startup From Enable. VOUT = 3.
PAGE 12
MCP16323 Note: Unless otherwise indicated, VIN = 12V, EN = Floating (internally pulled up), CIN = 20 µF, COUT = 2x22 µF, L = 4.7 µH, ILOAD = 200 mA, TA = +25°C. VOUT = 3.3V IOUT = 200 mA VIN = 6V to 10V FIGURE 2-31: DS22284A-page 12 Line Transient Response. © 2011 Microchip Technology Inc.
PAGE 13
MCP16323 3.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 3-1. TABLE 3-1: PIN FUNCTION TABLE MCP16323 3x3 QFN Symbol 1 SW Output switch node, connects to the inductor and the bootstrap capacitor 2 VIN Input supply voltage pin for power and internal biasing 3.1 Description 3 VIN 4 SGND 5 VFB Output voltage feedback pin. Connect VFB to VOUT for fixed version and output resistor divider for adjustable version.
PAGE 14
MCP16323 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 VIN > UVLO, unless the EN pin is pulled low. The maximum input voltage applied to the EN pin should not exceed 6V. 3.
PAGE 15
MCP16323 4.0 DETAILED DESCRIPTION 4.1 Device Overview The MCP16323 is a high input voltage step-down regulator, capable of supplying 3A 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.
PAGE 16
MCP16323 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. VIN UV CIN OTEMP VOUT EN Monitor and Control 4.
PAGE 17
MCP16323 4.2 Functional Description L 4.2.1 STEP-DOWN OR BUCK CONVERTER IL The MCP16323 is a synchronous, step-down or buck converter capable of stepping input voltages ranging from 6V to 18V down to 0.9V to 5V. 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.
PAGE 18
MCP16323 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.
PAGE 19
MCP16323 5.0 APPLICATION INFORMATION 5.0.1 TYPICAL APPLICATIONS The MCP16323 synchronous step-down converter operates over a wide input range, up to 18V maximum. Typical applications include generating a bias or VDD voltage for PIC® microcontrollers, digital control system bias supply for AC-DC converters and 12V industrial input and similar applications. 5.0.2 ADJUSTABLE OUTPUT VOLTAGE CALCULATIONS 5.0.
PAGE 20
MCP16323 TABLE 5-1: CAPACITOR VALUE RANGE Parameter Min Max COUT 33 µF None 5.0.6 INDUCTOR SELECTION The MCP16323 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. EQUATION 5-3: INDUCTOR CURRENT RIPPLE V L Δ I L = -----L- × t ON EXAMPLE 5-3: MCP16323 PEAK INDUCTOR CURRENT – 3A VIN = 12V VOUT = 3.3V IOUT = 3A L = 4.
PAGE 21
MCP16323 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 MCP16323 to minimize the loop area.
PAGE 22
MCP16323 CBOOST BOOST VOUT 0.9V to 5V L SW VIN 6.0V to 18V VIN MCP16323 10Ω CIN RTOP COUT VFB VOUT RBOT RPG EN PG SGND FIGURE 5-2: TABLE 5-3: Recommended Layout – Schematic. RECOMMENDED LAYOUT COMPONENTS Component Value CIN 2 x 10 µF COUT 2 x 22 µF L 4.7 µH RTOP 36.5 kΩ RBOT 10 kΩ RPG 10 kΩ CBOOST 22 nF DS22284A-page 22 PGND © 2011 Microchip Technology Inc.
PAGE 23
MCP16323 6.0 PACKAGING INFORMATION 6.1 Package Marking Information 16-Lead QFN (3x3x0.9 mm) Example Part Number Legend: XX...
PAGE 27
MCP16323 APPENDIX A: REVISION HISTORY Revision A (December 2011) • Original Release of this Document. © 2011 Microchip Technology Inc.
PAGE 29
MCP16323 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 -XXX /XX Tape and Reel Output Temperature Package Range Voltage Device: MCP16323T: Output Voltage 150 180 250 330 500 ADJ Temperature Range: E Package: X = = = = = = High-Efficiency Synchronous Buck Regulator (Tape and Reel) (QFN) Examples: a) MCP16323T-150E/NG: b) MCP16323T-ADJE/NG: Tape and Reel, 1.
PAGE 31
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.
PAGE 32
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