HF920
900V, Fixed-Frequency, Offline Regulator
w/ Ultra-Low Standby Power Consumption
HF920 Rev. 1.01 www.MonolithicPower.com 1
2/9/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.HF920
The Future of Analog IC Technology
DESCRIPTION
The HF920 is a flyback regulator with a
monolithic, 900V MOSFET. The HF920
provides excellent power regulation in AC/DC
applications that require high reliability, such as
smart meters, large appliances, industrial
controls, and products powered by poor AC
grids. The HF920 requires a minimal number of
external components.
The HF920 uses peak-current-mode control to
provide excellent transient response and easy
loop compensation. When the output power
falls below a given level, the regulator enters
burst mode. The IC consumption is also
specially optimized. As a result, the HF920
achieves very low power consumption during
standby conditions.
MPS’s proprietary, 900V, monolithic process
enables an over-temperature protection (OTP)
that is on the same silicon as the 900V power
MOSFET, offering the most precise thermal
protection. The HF920 also offers a full suite of
protection features such as VCC under-voltage
lockout (UVLO), overload protection (OLP),
over-voltage protection (OVP), and short-circuit
protection (SCP).
The HF920 is designed to minimize
electromagnetic interference for power line
communications (PLC) in home and building
automation applications. The operating
frequency is programmed externally with a
single resistor, so the power supply’s radiated
energy can be designed to block interference to
the PLC. In addition to the programmable
frequency, the HF920 employs frequency
jittering that reduces the noise level and EMI
filter cost greatly.
Frequency-doubling mode operation can be
enabled through a simple external set-up. With
this special operation mode, the switching
frequency is doubled when the converter runs
into an over-power condition. In this way, the
converter is able to handle up to a 50%
decrease of the transformer inductance caused
by external magnetizing interference.
FEATURES
Monolithic 900V/15Ω MOSFET and High-
Voltage Current Source
Fixed Switching Frequency, Programmable
up to 150kHz
Current-Mode Control Scheme
Frequency Jittering
Low Standby Power Consumption via Active
Burst Mode
<30mW No-Load Consumption
Frequency Doubling Operation Mode
Internal Leading-Edge Blanking (LEB)
Built-In Soft-Start (SS) Function
Internal Slope Compensation
External Input PRO Pin Protection with
Hysteresis and Auto-Restart Recovery
Over-Temperature Protection (OTP)
VCC Under-Voltage Lockout (UVLO) with
Hysteresis
Over-Voltage Protection (OVP) on VCC
Time-Based Overload Protection (OLP)
Short-Circuit Protection (SCP)
Available in SOIC8-7A and SOIC14-11
Packages
APPLICATIONS
E-Meters
Industrial Controls
Large Appliances
ll MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. Fo
MPS green status, please visit the MPS website under Quality Assurance.
“MPS” and “The Future of Analog IC Technology” are registered trademarks o
Monolithic Power Systems, Inc.
Table 1: Maximum Output Power
Package
P
MAX
(W)
85Vac~420Vac 230Vac±15%
SOIC8-7A 6.5 9.5
SOIC14-11 7 10
NOTES:
The maximum output power is limited by junction
temperature.
Test is done under T
A
= 50°C. The test board is placed into a
box about 20cm*15cm*10cm.
To reduce V
DS
, the turns ratio is set to 5.
Single output, V
OUT
= 12.5V.
GND of the SOIC8-7A package is connected to a 3cm
2
copper area with exposed copper strips. GND of the
SOIC14-11 package is connected to a 2.5cm
2
copper area.
Working condition under minimum input voltage is set to
BCM.