ICE3RBR0665JZ Datasheet, PDF (8/31 Pages) Infineon Technologies AG – Off-Line SMPS Current Mode Controller with integrated 650V

ICE3RBR0665JZ
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.
3.1
Introduction
ICE3RBR0665JZ (ICE3RBRxx65JZ series) is derived
from ICE3BRxx65J in DIP-7 package. It has more
robust design and can work to -40°C.
A high voltage Startup Cell is integrated into the IC
which is switched off once the Undervoltage Lockout
on-threshold of 18V is exceeded. This Startup Cell is
part of the integrated CoolMOS^®. The external startup
resistor is no longer necessary as this Startup Cell is
connected to the Drain. Power losses are therefore
reduced. This increases the efficiency under light load
conditions drastically.
The particular features are the active burst mode,
propagation delay compensation, modulated gate
driving, auto-restart protection for Vcc overvoltage,
over temperature, over load, open loop, built-in soft
start, blanking window and frequency jitter. It provides
the flexibility to increase the blanking window by simply
addition of a capacitor in BA pin. In order to further
increase the flexibility of the protection feature, an
external auto-restart enable features are added.
The intelligent Active Burst Mode can effectively obtain
the lowest Standby Power at light load and no load
conditions. After entering the burst mode, there is still a
full control of the power conversion to the output
through the optocoupler, that is used for the normal
PWM control. The response on load jumps is optimized
and the voltage ripple on V_out is minimized. The V_out is
on well controlled in this mode.
The usually external connected RC-filter in the
feedback line after the optocoupler is integrated in the
IC to reduce the external part count.
Adopting the BiCMOS technology, it can increase the
design flexibility as the Vcc voltage range is increased
to 25V.
It has a built-in 20ms soft start function.
There are 2 modes of blanking time for high load
jumps; the basic mode and the extendable mode. The
blanking time for the basic mode is set at 20ms while
the extendable mode will increase the blanking time by
adding an external capacitor at the BA pin in addition to
the basic mode blanking time. During this blanking time
window the system can give the maximum power to the
loading.
In order to increase the robustness and safety of the
system, the IC provides Auto Restart protection. The
Auto Restart Mode reduces the average power
conversion to a minimum level under unsafe operating
conditions. This is necessary for a prolonged fault
condition which could otherwise lead to a destruction of
the SMPS over time. Once the malfunction is removed,
normal operation is automatically retained after the
next Start Up Phase. To make the protection more
flexible, an external auto-restart enable pin is provided.
When the pin is triggered, the switching pulse at gate
will stop and the IC enters the auto-restart mode after
the pre-defined spike blanking time.
The internal precise peak current control reduces the
costs for the transformer and the secondary diode. The
influence of the change in the input voltage on the
maximum power limitation can be avoided together
with the integrated Propagation Delay Compensation.
Therefore the maximum power is nearly independent
on the input voltage, which is required for wide range
SMPS. Thus there is no need for the over-sizing of the
SMPS, e.g. the transformer and the output diode.
Furthermore, it implements the frequency jitter mode to
the switching clock such that the EMI noise will be
effectively reduced.
3.2
Power Management
Drain
VCC
Startup Cell
CoolMOS^®
Power Management
Internal Bias
Power-Down Reset
Soft Start block
Undervoltage Lockout
18V
10.5V
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
Version 2.0
8
7 Jun 2013