IP1837TRPBF International Rectifier, IP1837TRPBF Datasheet - Page 20
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
DESIGN PROCEDURE
APPLICATION INFORMATION
Design Example
The following example is a typical application for iP1837.
The application circuit is shown on page 1.
ENABLING THE IP1837
As explained earlier, the precise threshold of the Enable
lends itself well to implementation of a UVLO for the
Bus Voltage.
For a typical Enable threshold of V
For a V
choice.
PROGRAMMING THE FREQUENCY
For F
s
V
V
I
ΔV
ΔV
F
V
= 600 kHz, select R
R
o
s
in
o
= 35A
in
in
= 1.8V
= 600kHz
2
= 12V (13.2V max)
o
o
(min)
(min)
(transient) ≤ ±90mV for ΔIo = 10.5A @ 2.5A/µs
(ripple) ≤ ±13.5mV (±0.75%)
R
= 10.2V, R
*
20
1
V
R
in(
1
R
min
iP1837
March 3, 2011 | V1.24
2
V
R
Enable
EN
)
2
1
= 49.9K and R
V
t
= 36.5 kΩ, using Table 1.
V
EN
EN
1.2
EN
= 1.2 V
2
= 7.5K is a good
Vin
R
R
(6)
(7)
1
2
Highly Integrated 35A Single‐input Voltage,
Synchronous Buck Regulator
OUTPUT VOLTAGE PROGRAMMING
Output voltage is programmed by the reference voltage
and external voltage divider. If the remote sense feature is
used, the divider is connected to the Vosp and Vosm pins.
If only local sensing is used for feedback, with the remote
sense amplifier used only in the over‐voltage protection,
circuit, the resistive divider should be connected to the
Fb pin.
For this design, with high output current requirements, we
choose to use the true differential remote sense feature.
The Fb pin is the inverting input of the error amplifier,
which is internally referenced to 0.6V. This references the
output of the remote sense amplifier to 0.6V also. In order
to satisfy this condition, the voltage between the Vosp and
Vosm pins of the error amplifier should be 0.6V when the
output is at its desired value. The output voltage is defined
by using the following equation:
when an external resistor divider is connected to the
output as shown in Figure 16.
Equation (8) can be rewritten as:
R
Figure 16: Typical application of the iP1837
V
top
o
for programming the output voltage
V
ref
R
iP1837
bot
1
Vosp
V
R
R
o
V
bot
top
ref
V
ref
Vout
iP1837
R
R
top
bot
(9)
(8)
97600