IP1837TRPBF International Rectifier, IP1837TRPBF Datasheet - Page 16
IP1837TRPBF
Manufacturer Part Number
IP1837TRPBF
Description
IC DC-DC REG SYNC BUCK LGA
Manufacturer
International Rectifier
Series
iPOWIR™r
Type
Step-Down (Buck), PWM - Voltage Moder
Datasheet
1.IP1837TRPBF.pdf
(40 pages)
Specifications of IP1837TRPBF
Internal Switch(s)
Yes
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
0.6 V ~ 12 V
Current - Output
35A
Frequency - Switching
250kHz ~ 1.5MHz
Voltage - Input
1.5 V ~ 16 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
*
Package / Case
*
Package
LGA - 7.7 x 7.7
Circuit
Single Output
Iout (a)
35
Switch Freq (khz)
250 - 1500
Input Range (v)
1.5 - 16
Output Range (v)
0.6 - 0.75*Vin
Internal Bias Ldo
Yes
Ocp Otp Uvlo Pre-bias Soft Start And
Remote Sense + Body Tracking + Temp Comp OCP
Pbf
PbF Option Available
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
IP1837TRPBF
Manufacturer:
IR
Quantity:
20 000
OPERATING FREQUENCY
The switching frequency can be programmed between
250kHz – 1500kHz by connecting an external resistor from
R
versus R
T
SHUTDOWN
The iP1837 can be shutdown by pulling the Enable pin
below its 1 V threshold. This will tri‐state both, the high
side driver as well as the low side driver.
TEMPERATURE‐COMPENSATED
OVER‐CURRENT PROTECTION
The over current protection is performed by sensing
current through the R
method enhances the converter’s efficiency and reduces
cost by eliminating a current sense resistor. As shown in
Figure 11, an external resistor (R
between OCSet pin and the switch node (SW) which sets
the current limit set point.
ABLE
T
Figure 10: Theoretical operation waveforms during soft‐start
pin to Gnd. Table 1 tabulates the oscillator frequency
1:
S
T
.
WITCHING
16
Vss
Vout
Fsw (kHz)
POR
1000
1500
250
300
400
450
500
600
800
0.2V
F
March 3, 2011 | V1.24
t1
REQUENCY VS
DS(on)
0.8V
t2
of low side MOSFET. This
t3
R
.
T
E
OCSet
(kohm)
XTERNAL
88.7
73.2
54.9
48.7
44.2
36.5
27.4
22.1
14
) is connected
R
ESISTOR
Highly Integrated 35A Single‐input Voltage,
(R
T
)
Synchronous Buck Regulator
An internal current source sources current (I
the OCSet pin. The internal current source develops a
voltage across ROCSet. When the low side MOSFET is
turned on, the inductor current flows through Q2 and
results in a voltage at OCSet which is given by:
An over current is detected if the OCSet pin goes below
ground. Hence, at the current limit threshold, V
Then, for a current limit setting I
follows:
It should be noted that the iP1837 uses a temperature
compensated overcurrent protection scheme, i.e., I
varies with temperature with the same temperature
coeffecient as R
and is independent of temperature.
The value of Rocset calculated above is realized as a
parallel combination of an internal 2.7K resistor and an
external resistor connected between the Rocset and SW
pins. Table 2 shows the selection of the external Rocset
resistor for various values of the trip load current I
Vcc = 3.3V.
Control
Hiccup
V
OCSet
Figure 11: Connection of over‐current sensing resistor
R
OCSet
(
I
OCSet
R
DS(on)
DS
(
on
, so that I
I
R
+
-
OCSet
)
OCSet
*
I
IntV
)
Ltrip
Ltrip
CC
(
Q1
Q2
R
Ltrip
depends only on Rocset
DS
I
OCSet
,
(on
R
OCSet
PGnd
)
Vin
I
iP1837
is calculated as
L
)
OCSet
(3)
OCset
) out of
R
otrip
97600
=0.
OCSet
OCSet
SW
OCSet
(2)
at