Datasheet

ManualsBrandsMicrochip ManualsDC / DC ControllersPWM Boost Regulator 3.6 ... 34V 1A SOT-23

 2018 Microchip Technology Inc. DS20006034B-page 1

MIC2288

Features

• 2.5V to 10V Input Voltage Range

• Output Voltage Adjustable to 34V

• Over 1A Switch Current

• 1.2 MHz PWM Operation

• Stable with Ceramic Capacitors

• <1% Line and Load Regulation

• Low Output Voltage Ripple

• <1 µA Shutdown Current

• Undervoltage Lockout

• Output Overvoltage Protection (MIC2288YML)

• Overtemperature Shutdown

• Thin SOT23-5 Package Option

• 2 mm x 2 mm leadless DFN-8 Package Option

• –40°C to +125°C Junction Temperature Range

Applications

• Organic EL Power Supply

• TFT-LCD Bias Supply

• 12V Supply for DSL Applications

• Multi-Output DC/DC Converters

• Positive and Negative Output Regulators

• SEPIC Converters

General Description

The MIC2288 is a 1.2 MHz PWM, DC/DC boost

switching regulator available in low-profile Thin SOT23

and 2 mm x 2 mm DFN package options. High power

density is achieved with the MIC2288’s internal 34V/1A

switch, allowing it to power large loads in a tiny

footprint.

The MIC2288 implements a constant frequency,

1.2 MHz PWM, current mode control scheme with

internal compensation that offers excellent transient

response and output regulation performance. The high

frequency operation saves board space by allowing

small, low-profile, external components. The fixed

frequency PWM topology also reduces spurious

switching noise and ripple to the input power source.

The MIC2288 is available in a low-profile Thin SOT23-5

package and a 2 mm x 2 mm DFN-8 leadless package.

The DFN package option has an output overvoltage

protection feature.

The MIC2288 has a junction temperature range of

–40°C to +125°C.

Package Types

MIC2288

DFN-8 (ML)

(Top View)

MIC2288

Thin SOT23-5 (D5)

(Top View)

OVP

VIN

AGND

PGND

GND

EN VIN

1A, 1.2 MHz PWM Boost Converter in Thin SOT23 and DFN Packages

Summary of content (24 pages)

PAGE 1
MIC2288 1A, 1.2 MHz PWM Boost Converter in Thin SOT23 and DFN Packages Features General Description • • • • • • • • • • • • • • The MIC2288 is a 1.2 MHz PWM, DC/DC boost switching regulator available in low-profile Thin SOT23 and 2 mm x 2 mm DFN package options. High power density is achieved with the MIC2288’s internal 34V/1A switch, allowing it to power large loads in a tiny footprint. 2.5V to 10V Input Voltage Range Output Voltage Adjustable to 34V Over 1A Switch Current 1.
PAGE 2
MIC2288 Typical Application Circuit L1 10μH VIN VOUT 15V MIC2288YD5 5 4 1-Cell Li Ion C1 2.2μF SW VIN FB EN 1 R1 3 R2 GND C2 10μF 2 Functional Block Diagram VIN FB OVP* EN OVP* SW PWM Generator gm VREF 1.24V Σ 1.2MHz Oscillator Ramp Generator CA GND *OVP available on DFN package option only. DS20006034B-page 2  2018 Microchip Technology Inc.
PAGE 3
MIC2288 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings † Supply Voltage (VIN) .................................................................................................................................................+12V Switch Voltage (VSW) ................................................................................................................................. –0.3V to +34V Enable Pin Voltage (VEN) ...................................................................................
PAGE 4
MIC2288 ELECTRICAL CHARACTERISTICS Electrical Characteristics: TA = +25°C, VIN = VEN = 3.6V, VOUT = 10V, IOUT = 20 mA, unless otherwise noted. Bold values indicate –40°C ≤ TJ ≤ ±125°C. Note 1 Parameter Sym. Min. Typ. Max. Units Supply Voltage Range VIN 2.5 — 10 V — Undervoltage Lockout VUVLO 1.8 2.1 2.4 V — Quiescent Current IVIN — 2.8 5 mA VFB = 2V, not switching Shutdown Current ISD — 0.1 1 µA VEN = 0V, Note 2 Feedback Voltage VFB 1.227 1.24 1.252 1.215 — 1.
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MIC2288 TEMPERATURE SPECIFICATIONS Parameters Sym. Min. Typ. Max.
PAGE 6
MIC2288 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. Note: 91 1.8 89 1.6 V IN = 4.2V 1.
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MIC2288 . MAXIMUM DUTY CYCLE (%) 600 500 400 300 200 V IN = 3.6V 100 0 0 Switch Saturation vs. Switch FIGURE 2-10: Supply Voltage. 700 99 600 97 500 400 300 200 100 V IN = 3.6V I = 500mA SW 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) FIGURE 2-8: Temperature. FREQUENCY (MHz) 1000 100 98 96 94 92 90 88 86 84 82 80 2.5 MAXIMUM DUTY CYCLE (%) SWITCH SATURATION VOLTAGE (mV) FIGURE 2-7: Current. 200 400 600 800 SWITCH CURRENT (mA) Switch Saturation vs.
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3.6VIN 12VOUT 150mA Load OUTPUT VOLTAGE (100mV/div) AC-Coupled 10mA Time (400μs/div) 4.2V 3.2V 12VOUT 150mA Load Line Transient Response. Load Transient Response. OUTPUT VOLTAGE (50mV/div) FIGURE 2-15: SWITCH SATURATION (5V/div) Enable Characteristics. INPUT VOLTAGE (2V/div) DS20006034B-page 8 3.
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MIC2288 3.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 3-1. TABLE 3-1: PIN FUNCTION TABLE Pin Number TSOT23-5 Pin Number DFN-8 Pin Name 1 7 SW 2 — GND 3 6 FB Feedback (Input): 1.24V output voltage sense node. 4 3 EN Enable (input): Logic-high enables regulator. Logic-low shuts down regulator. Do not leave floating. 5 2 VIN Supply (Input): 2.5V to 10V input voltage.
PAGE 10
MIC2288 4.0 FUNCTIONAL DESCRIPTION The MIC2288 is a constant frequency, PWM current mode boost regulator. See the Functional Block Diagram. The MIC2288 is composed of an oscillator, slope compensation ramp generator, current amplifier, gm error amplifier, PWM generator, and a 1A bipolar output transistor. The oscillator generates a 1.2 MHz clock. The clock’s two functions are to trigger the PWM generator that turns on the output transistor and to reset the slope compensation ramp generator.
PAGE 11
MIC2288 5.0 APPLICATION INFORMATION 5.1 DC/DC PWM Boost Conversion The MIC2288 is a constant-frequency boost converter. It operates by taking a DC input voltage and regulating a higher DC output voltage. Figure 5-1 shows a typical circuit. Boost regulation is achieved by turning on an internal switch, which draws current through the inductor (L1).
PAGE 12
MIC2288 5.4.2 OUTPUT CAPACITOR Output capacitor selection is also a trade-off between performance, size, and cost. Increasing output capacitance will lead to an improved transient response, but also an increase in size and cost. X5R or X7R dielectric ceramic capacitors are recommended for designs with the MIC2288. Y5V values may be used but to compensate their drift over temperature, more capacitance is required. The following table shows the recommended ceramic (X5R) output capacitor value vs.
PAGE 13
MIC2288 6.0 APPLICATION CIRCUITS L1 4.7μH VIN 3V to 4.2V VOUT 5V @ 400mA D1 MIC2288YML C1 4.7μF 6.3V VIN OVP FB R2 1.87kΩ GND GND FIGURE 6-1: @ 400 mA. VOUT 12V @ 100mA D1 MIC2288YML R1 5.62kΩ SW EN L1 10μH VIN 3V to 4.2V C2 22μF 6.3V VIN C1 2.2μF 10V R1 42.3kΩ SW OVP EN FB R2 5kΩ GND GND 3.0V to 4.2V VIN to 5VOUT GND C2 10μF 16V GND 3.0V to 4.2V VIN to 12VOUT FIGURE 6-3: @ 100 mA. Ref Description Part Number Vendor Ref Description Part Number Vendor C1 4.7 µF, 6.
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MIC2288 L1 10μH VIN 3V to 4.2V VOUT 24V @ 50mA D1 L1 10μH VIN 5V MIC2288YML VIN C1 2.2μF 10V MIC2288YML R1 18.2kΩ SW OVP EN FB R2 1kΩ GND GND FIGURE 6-5: @ 50 mA. Ref C2 4.7μF 25V VIN C1 2.2μF 10V R1 43.2kΩ SW OVP EN FB R2 5kΩ GND GND 3.0V to 4.2V VIN to 24VOUT Description VOUT 12V @ 250mA D1 Part Number Vendor GND FIGURE 6-7: C2 10μF 16V GND 5VIN to 12VOUT @ 250 mA. Ref Description Part Number Vendor 08052D225KAT AVX C1 2.
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MIC2288 7.0 PACKAGING INFORMATION 7.1 Package Marking Information 5-Lead TSOT23* XXXX NNN 8-Lead TDFN* XXX NNN Legend: XX...X Y YY WW NNN e3 * Example SHAA 943 Example SJA 408 Product code or customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Alphanumeric traceability code Pb-free JEDEC® designator for Matte Tin (Sn) This package is Pb-free.
PAGE 16
MIC2288 5-Lead Thin SOT23 Package Outline & Recommended Land Pattern Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging. DS20006034B-page 16  2018 Microchip Technology Inc.
PAGE 17
MIC2288 8-Lead 2 mm x 2 mm Thin DFN Package Outline and Recommended Land Pattern Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging.  2018 Microchip Technology Inc.
PAGE 18
MIC2288 NOTES: DS20006034B-page 18  2018 Microchip Technology Inc.
PAGE 19
MIC2288 APPENDIX A: REVISION HISTORY Revision A (May 2018) • Converted Micrel document MIC2288 to Microchip data sheet template DS20006034A. • Minor grammatical text changes throughout. • Updated Low Output Voltage Ripple in Features. • Added clarification to EN description in Table 3-1. • Updated drawing for EN in Figure 5-1. • Updated drawings and figure captions for each entry in Section 6.0 “Application Circuits”. Revision B (September 2018) • Updated values for C2 in the table beneath Figure 6-3.
PAGE 20
MIC2288 NOTES: DS20006034B-page 20  2018 Microchip Technology Inc.
PAGE 21
MIC2288 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, contact your local Microchip representative or sales office. Examples: Device X XX -XX Part No. Junction Temp. Range Package Media Type 1A, 1.
PAGE 22
MIC2288 NOTES: DS20006034B-page 22  2018 Microchip Technology Inc.
PAGE 23
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 24
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