IR3473MTRPBF International Rectifier, IR3473MTRPBF Datasheet - Page 13
IR3473MTRPBF
Manufacturer Part Number
IR3473MTRPBF
Description
IC BUCK SYNC ADJ 6A PQFN
Manufacturer
International Rectifier
Series
SupIRBuck™r
Type
Step-Down (Buck), PWM - Current Moder
Datasheet
1.IR3473MTRPBF.pdf
(21 pages)
Specifications of IR3473MTRPBF
Internal Switch(s)
Yes
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
0.5 V ~ 12 V
Current - Output
6A
Frequency - Switching
Up to 750kHz
Voltage - Input
3 V ~ 27 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
*
Package / Case
*
Primary Input Voltage
27V
No. Of Outputs
1
Output Voltage
12V
Output Current
6A
No. Of Pins
17
Operating Temperature Range
-40°C To +125°C
Peak Reflow Compatible (260 C)
Yes
Rohs Compliant
Yes
Leaded Process Compatible
Yes
Part Status
Preferred
Package
PQFN / 4 x 5
Circuit
Single Output
Iout (a)
6
Switch Freq (khz)
0 - 750
Input Range (v)
3.0 - 27
Output Range (v)
0.5 - 12
Ocp Otp Uvlo Pre-bias Soft Start And
Constant On-Time + PGOOD + EN + Temp Comp OCP
Digital Home Media
Yes
Mobile Computing
Yes
Industrial 24v Input
Yes
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
UNDER/OVER VOLTAGE MONITOR
The IR3473 monitors the voltage at the FB node through a
350ns filter. If the FB voltage is below the under voltage
threshold, UV# is set to LOW holding PGOOD to be LOW. If
the FB voltage is above the over voltage threshold, OV# is
set to LOW, the shutdown signal (SD) is set to HIGH,
MOSFET gates are turned off, and PGOOD signal is pulled
low. Toggling VCC or EN will allow the next start up. Figure
24 and 25 show PGOOD status change when UV/OV is
detected. The over voltage and under voltage thresholds
can be found in the Electrical Specification section.
Figure 24: Under/Over Voltage Monitor
13
Figure 25: Over Voltage Protection
February 16, 2011 | ADVANCED DATASHEET | V1.9 | PD97601
* typical filter delay
* typical filter delay
6A Highly Integrated SupIRBuck
OVER CURRENT MONITOR
The over current circuitry monitors the output current
during each switching cycle. The voltage across the lower
MOSFET, VPHASE, is monitored for over current and zero
crossing. The minimum lower gate interval allows time to
sample VPHASE.
The over current trip point is programmed with a resistor
from the ISET pin to PHASE pin, as shown in equation 4.
When over current is detected, the MOSFET gates are tri‐
state and SS voltage is pulled to 0V. This initiates a new
soft start cycle. If there is a total of four OC events, the
IR3473 will disable switching. Toggling VCC or EN will allow
the next start up.
UNDER VOLTAGE LOCK‐OUT
The IR3473 has VCC and EN under voltage lock‐out (UVLO)
protection. When either VCC or EN is below their UVLO
threshold, IR3473 is disabled. IR3473 will restart when
both VCC and EN are above their UVLO thresholds.
OVER TEMPERATURE PROTECTION
When the IR3473 exceeds its over temperature threshold,
the MOSFET gates are tri‐state and PGOOD is pulled low.
Switching resumes once temperature drops below the over
temperature hysteresis level.
Figure 26: Over Current Protection
R
SET
R
DSON
19
TM
I
A
OC
IR3473
(4)