NCP1237 datasheet(1/34 Pages) ONSEMI

部件名	NCP1237

功能描述	Fixed Frequency Current Mode Controller for Flyback Converters

PDF	34 Pages

Scroll/Zoom	100%

制造商	ONSEMI [ON Semiconductor]

网页	http://www.onsemi.com

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February, 2010 − Rev. 1

1

Publication Order Number:

NCP1237/D

NCP1237

Fixed Frequency Current

Mode Controller for Flyback

Converters

The NCP1237 is a new generation of the NCP12xx fixed−frequency

current−mode controllers featuring Dynamic Self−Supply (DSS),

pin−to−pin compatible with the previous generation.

The DSS function greatly simplifies the design of the auxiliary supply

and the VCC capacitor by activating the internal startup current source to

supply the controller during transients.

Due to its proprietary Soft−Skip

™ mode combined with frequency

foldback, the controller exhibits excellent efficiency in light load

condition while still achieving very low standby power consumption.

This Soft−Skip feature also dramatically reduces the risk of acoustic

noise, which enables the use of inexpensive transformers and

capacitors in the clamping network.

The NCP1237 features a dual−level timer−based fault detection that

controls the amount of transient peak power that the controller can

deliver for a limited time.

Internal frequency jittering, ramp compensation, and a versatile

latch input make this controller an excellent candidate for converters

where ruggedness and components cost are the key constraints.

In addition, the controller includes a new high voltage circuitry that

combines a startup current source and a brown−out / line OVP detector

able to sense the input voltage either from the rectified ac line or the dc

filtered bulk voltage.

Finally, due to a careful design, the precision of critical parameters

is well controlled over the entire temperature range (−40

°C to

+125

°C), enabling easier design and increased safety (e.g. ±5% for the

peak current limit,

±7% for the oscillator).

Features

• Timer−Based Transient Power and Overload

Protections with Auto−Recovery (Option B) or Latched

(Option A) Operation

• High−Voltage Current Source with DSS with Built−in

Brown−out and Line Overvoltage Protections

• Fixed−Frequency Current−Mode Operation with

Built−in Ramp Compensation

• Frequency Jittering for a Reduced EMI Signature

• Adjustable Overpower Compensation

• Latch−off Input for Severe Fault Conditions, with

Direct Connection of an NTC for Overtemperature

Protection (OTP)

• Protection Against Winding Short−Circuit

• Frequency Foldback transitioning into Soft−Skip for

Improved Performance in Standby

• 65 kHz Oscillator (100 kHz and 133 kHz Versions

Available Upon Request)

• VCC Operation up to 28 V

• Increased Precision on Critical Parameters

• ±1.0 A Peak Drive Capability

• 4.0 ms Soft−Start

• Internal Thermal Shutdown with Hysteresis

• These Devices are Pb−Free, Halogen Free/BFR Free

and are RoHS Compliant*

Typical Applications

• ac−dc Adapters for Notebooks, LCD, and Printers

• Offline Battery Chargers

• Consumer Electronic Power Supplies

• Auxiliary/Housekeeping Power Supplies

*For additional information on our Pb−Free strategy and soldering details, please

download the ON Semiconductor Soldering and Mounting Techniques

Reference Manual, SOLDERRM/D.

SOIC−7

CASE 751U

MARKING

DIAGRAM

http://onsemi.com

37Xff

ALYWX

G

1

8

37Xff = Specific Device Code

X = A or B

ff = 65, 00, or 33

A

= Assembly Location

L

= Wafer Lot

Y

= Year

W

= Work Week

G

= Pb−Free Package

See detailed ordering and shipping information in the package

dimensions section on page 32 of this data sheet.

ORDERING INFORMATION

类似零件编号 - NCP1237

制造商	部件名	数据表	功能描述
ON Semiconductor	NCP1237	280Kb / 41P	Fixed Frequency Current Mode Controller for Flyback Converters July, 2011 ??Rev. 4

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制造商	部件名	数据表	功能描述
ON Semiconductor	NCP1288	274Kb / 32P	Fixed Frequency Current Mode Controller for Flyback Converters February, 2010 ??Rev. 1
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	NCP1236AD65R2G	302Kb / 34P	Fixed Frequency Current Mode Controller for Flyback Converters April, 2013 ??Rev. 3
	NCP12400	4Mb / 46P	Fixed Frequency Current Mode Controller for Flyback Converters October, 2019 ??Rev. 5
	NCP12401	4Mb / 44P	Fixed Frequency Current Mode Controller for Flyback Converters July, 2020 ??Rev. 1
	NCP1246	1Mb / 41P	Fixed Frequency Current Mode Controller for Flyback Converters March, 2017 - Rev. 7
	NCP12400	4Mb / 47P	Fixed Frequency Current Mode Controller for Flyback Converters February, 2022 - Rev. 8

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NCP1237 数据表(PDF) 1 Page - ON Semiconductor

NCP1237 数据表(HTML) 1 Page - ON Semiconductor

类似零件编号 - NCP1237

类似说明 - NCP1237

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NCP1237 数据表(PDF) 1 Page - ON Semiconductor

NCP1237 数据表(HTML) 1 Page - ON Semiconductor

类似零件编号 - NCP1237

类似说明 - NCP1237

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