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BM1050AF-G Datasheet, PDF (1/51 Pages) Rohm – Quasi-Resonant Control DC/DC
Datasheet
Quasi-Resonant Control DC/DC
converter and Power Factor Correction
converter IC for AC/DC Converter
BM1050AF-G
●General Description
BM1050AF is compounded LSI of Power Factor Correction
converter (PFC) for harmonic solution and DC/DC converter
(DC/DC). Because DC/DC operates on Quasi-resonant
method, DC/DC contributes to Low EMI.
BM1050AF built in a HV starter circuit that tolerates 650V.
Because of putting the current sense resistors externally
both the PFC part and the DC/DC part, IC enables power
supply design free.
In the PFC part, IC adopts peak current control operation.
Suitable application is proposed by a various protection
circuit, such as the multiplier with a revision circuit on the AC
voltage falls, the load regulation revision circuit, and the
maximum power feed-forward circuit, etc.
Moreover, the frequency hopping function is built in and it
contributes to low EMI.
The Quasi-resonant system of a DC/DC part contributes to
low EMI because PFC operates by soft switching.
A burst mode is built in, so the power is reduced at light load.
Various protection functions, such as a soft start function, a
burst function, an over-current limiting for every cycle,
overvoltage protection, and over current protection, are built
in. The pin for communicated control with a controller and the
external stop pin are prepared; it proposes the system that
can be adapted for various applications.
●Basic specifications
 Operating Power Supply Voltage Range:
VCC:8.5 to 24.0V
 Operating Current:
QR ON (PFC OFF):1.20mA(pulse on)
QR ON (PFC OFF):1.00mA(pulse off)
QR ON (PFC ON):1.80mA(pulse on)
 Oscillation Frequency QR part :120kHz(FB=2.0V typ)
 Operating Temperature: -40℃ to +85℃

●Typical Application Circuit(s)
●Features
 Quasi-resonant circuit + PFC circuit
 Built-in HV Starter circuit
 Low consumption current (typ.10uA) when starter
circuit is OFF.
 Quasi resonant circuit
Max operating frequency(120kHz)
Frequency reduction function
Over-current limiting variable function
Pulse-by-pulse over-current protection circuit
Built-in Soft start
Voltage protection function (brown out) during low
input
ZT pin Over Voltage Protection
Output overload protection (auto recovery /latch
switching enabled)
250nsec Leading-Edge Blanking
 Power Factor Correction circuit
Peak current control (65kHz)
Frequency hopping function
Per-cycle over current protection circuit
Maximum power revision
the multiplier with a revision circuit when the AC
voltage falls
the load change measure circuit
 Selectable protection method by LATCH/AUTOR
terminal.
LATCH/AUTOR=H : Latch
LATCH/AUTOR=L : Auto recovery
 External stop function (COMP pin)
 AC input voltage stop detected function (ACDET)
 Built-in PFC stop terminal (PFCON/OFF)
●Package(s)
SOP24 15.0mm×5.40mm ×1.80mm pitch1.27mm
(Typ.) (Typ.) (TYP.) (TYP.)
●Applications
TV, AC adapters, printers, LED lighting
Figure 1. Application circuit
○Product structure:Silicon monolithic integrated circuit
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© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This product is not designed for protection against radioactive rays
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TSZ02201-0F2F0A200140-1-2
10.Apr.2015 Rev.003