IR11662SPBF International Rectifier, IR11662SPBF Datasheet - Page 13

• Manufacturer Part Number: IR11662SPBF
• Description: IC CNTROL SMART RECTIFIER 8-SOIC
• Manufacturer: International Rectifier
• Series: Advanced Smart Rectifier™r

Specifications of IR11662SPBF

• Configuration: High-Side
• Input Type: Non-Inverting
• Delay Time: 60ns
• Current - Peak: 1A
• Number Of Configurations: 1
• Number Of Outputs: 1
• Voltage - Supply: 11.4 V ~ 18 V
• Operating Temperature: -25°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: *
• Device Type: MOSFET
• Module Configuration: Half Bridge
• Peak Output Current: 4A
• Input Delay: 60ns
• Output Delay: 50ns
• Supply Voltage Range: 11.4V To 18V
• Driver Case Style: SOIC
• No. Of Pins: 8
• Rohs Compliant: Yes
• Part Status: Active and Preferred
• Package: 8-Pin SOIC(NB)
• Circuit: Switching Regulator Controller
• Topology: Flyback / Resonant Half-Bridge
• Current Mode: Discontinuous / Critical
• Vcc (min): 11.4
• Vcc (max): 18
• Vout (max): 200
• Iout (a): +1 / -4
• Switch Freq (khz): up to 500kHz
• Vgate Clamp (v): 10.7
• Programmability: MOT / OVT
• Enable Pin: Yes
• Isleep (ua): 200
• Automatic Mot Protection: Yes
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• High Side Voltage - Max (bootstrap): -

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General Description
The IR11662 Smart Rectifier IC can emulate the operation of diode rectifier by properly driving a
Synchronous Rectifier (SR) MOSFET. The direction of the rectified current is sensed by the input comparator
using the power MOSFET R
accordingly.
Internal blanking logic is used to prevent spurious transitions and guarantee operation in continuous (CCM),
discontinuous (DCM) and critical (CrCM) conduction mode.
IR11662 is suitable for Flyback and Resonant Half-Bridge topologies.
Flyback Application
The modes of operation for a Flyback circuit differ mainly for the turn-off phase of the SR switch, while the
turn-on phase of the secondary switch (which corresponds to the turn off of the primary side switch) is
identical.
Turn-on phase
When the conduction phase of the SR FET is initiated, current will start flowing through its body diode,
generating a negative V
the one caused by the MOSFET on resistance and therefore will trigger the turn-on threshold V
At that point the IR11662 will drive the gate of MOSFET on which will in turn cause the conduction voltage
VDS to drop down. This drop is usually accompanied by some amount of ringing, that can trigger the input
comparator to turn off; hence,
power MOSFET on for a minimum amount of time.
The programmed MOT will limit also the minimum duty cycle of the SR MOSFET and, as a consequence, the
max duty cycle of the primary side switch.
DCM/CrCM Turn-off phase
Once the SR MOSFET has been turned on, it will remain on until the rectified current will decay to the level
where V
operation.
In DCM the current will cross the threshold with a relatively low dI/dt. Once the threshold is crossed, the
current will start flowing again thru the body diode, causing the V
the amount of residual current, V
blanked for a certain amount of time (T
The blanking time is internally set. As soon as V
is terminated and the IC is ready for next conduction cycle.
DS
will cross the turn-off threshold V
DS
V
voltage across it. The body diode has generally a much higher voltage drop than
TH2
Dson
a Minimum On Time (MOT) blanking period is used that will maintain the
Figure 1: Input comparator thresholds
DS
as a shunt resistance and the GATE pin of the MOSFET is driven
may trigger once again the turn on threshold: for this reason V
BLANK
V
TH1
) after V
TH1
DS
V
. This will happen differently depending on the mode of
Gate
TH1
crosses the positive threshold V
13
has been triggered.
DS
voltage to jump negative. Depending on
V
TH3
TH3
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V
DS
also the blanking time
IR11662S
TH2
.
TH2
is