ICE3BR2280JZ Datasheet, PDF (8/34 Pages) Infineon Technologies AG – Off-Line SMPS Current Mode Controller with integrated 800V

CoolSET^®-F3R80
ICE3BR2280JZ
Functional Description
3 Functional Description
All values which are used in the functional description
are typical values. For calculating the worst cases the
min/max values which can be found in section 4
Electrical Characteristics have to be considered.
CoolSET^® F3R80 is a complete solution for the low
power SMPS application.
3.2 Power Management
3.1
Introduction
CoolSET^®-F3R80 brownout and jitter 800V version
(ICE3BR2280JZ) is the enhanced version of the
CoolSET^®-F3R 650V version (ICE3BRxx65J). It is
particular good for high voltage margin low power
SMPS application such as auxiliary power supply for
PC and server. The major characteristics are that the
IC is developed with 800V CoolMOS^® with start up cell,
having adjustable brownout feature, running at 65KHz
switching frequency and packed in DIP-7 package. It is
derived from F3R 650V version. Thus most of the good
features are retained. Besides, it includes some
enhanced features and new features.
The retained good features include BiCMOS
technology to reduce power consumption and increase
the Vcc voltage range, cycle by cycle current mode
control, built-in 10ms soft start to reduce the stress of
switching elements during start up, built-in 20ms and
extended blanking time for short period of peak power
before entering protection, active burst mode for lowest
standby power and propagation delay compensation
for close power limit between high line and low line,
frequency jittering for low EMI performance, the built-in
auto-restart mode protections for open loop, over load,
Vcc OVP, Vcc under voltage, etc. and also the most
flexible external auto-restart enable, etc.
The enhanced features include narrowing the feedback
voltage swing from 0.5V to 0.3V during burst mode so
that the output voltage ripple can be reduced by 40%,
reduction of the fast voltage fall time of the MOSFET by
increasing the soft turn-on time and addition of 50W
turn-on resistor, faster start up time by optimizing the
Vcc capacitor to 10uF and over temperature protection
with 50°C hysteresis.
The new features include adjustable brownout for
reliable output performance, selectable entry and exit
burst mode so that smaller entry/exit power to burst
mode or even no burst mode is possible and the
propagation delay compensation for burst mode so that
the entry/exit burst mode power is close between high
line and low line.
In summary, the CoolSET^® F3R80 provides good
voltage margin of MOSFET, lowest standby power,
flexible burst level, reduced output ripple during burst
mode, reliable output with brownout feature, accurate
power limit for both maximum power and burst power,
low EMI with frequency jittering and soft gate drive,
built-in and flexible protections, etc. Therefore,
Drain
Startup Cell
VCC
CoolMOS^®
Power Management
Internal Bias
Undervoltage Lockout
17V
10.5V
Power-Down Reset
Soft Start block
Voltage
Reference
5.0V
Auto Restart
Mode
Active Burst
Mode
Figure 3 Power Management
The Undervoltage Lockout monitors the external
supply voltage V_VCC. When the SMPS is plugged to the
main line the internal Startup Cell is biased and starts
to charge the external capacitor C_VCC which is
connected to the VCC pin. This VCC charge current is
controlled to 0.9mA by the Startup Cell. When the V_VCC
exceeds the on-threshold V_CCon=17V the bias circuit
are switched on. Then the Startup Cell is switched off
by the Undervoltage Lockout and therefore no power
losses present due to the connection of the Startup Cell
to the Drain voltage. To avoid uncontrolled ringing at
switch-on, a hysteresis start up voltage is implemented.
The switch-off of the controller can only take place
when V_VCC falls below 10.5V after normal operation
was entered. The maximum current consumption
before the controller is activated is about 200mA.
When V_VCC falls below the off-threshold V_CCoff=10.5V,
the bias circuit is switched off and the soft start counter
is reset. Thus it ensures that at every startup cycle the
soft start starts at zero.
The internal bias circuit is switched off if Auto Restart
Mode is entered. The current consumption is then
reduced to 320mA.
Version 2.1a
8
11 Jan 2012