IP1827TRPBF International Rectifier, IP1827TRPBF Datasheet - Page 16

• Manufacturer Part Number: IP1827TRPBF
• Description: IC DC-DC REG SYNC BUCK LGA
• Manufacturer: International Rectifier
• Series: iPOWIR™r
• Type: Step-Down (Buck), PWM - Voltage Moder

Specifications of IP1827TRPBF

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.6 V ~ 12 V
• Current - Output: 25A
• Frequency - Switching: 225kHz ~ 1.65MHz
• 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): 25
• 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

An overcorrect detection trips the OCP comparator,
latches OCP signal and cycles the soft start function in
hiccup mode. The hiccup is performed by shorting the
soft‐start capacitor to ground and counting the number of
switching cycles. The Soft Start pin is held low until 4096
cycles have been completed. Following this, the OCP signal
resets and the converter recovers. After every soft start
cycle, the converter stays in this mode until the overload
or short circuit is removed.
For the iP1827, the Sync FET is turned OFF on the falling
edge of a PWMSet or Clock signal that has duration of 25%
of the switching period. For operation at the maximum
duty cycle, the OCP circuit samples current for 40 ns,
starting 40 ns after the low drive signal for the Sync FET >
70% of PVcc.
T
ABLE
2:
O
VERCURRENT SETTING VS
16
I
otrip
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
(A)
January 24, 2011 | V1.2
External Rocset (kohm)
.
E
XTERNAL
Open
2.61
2.94
3.24
3.65
4.02
4.53
4.99
5.62
6.34
7.15
8.06
9.09
10.5
12.1
14.3
16.9
20.5
26.1
48.7
80.6
226
34
R
OCSET
Highly Integrated 25A Single‐input Voltage,
Synchronous Buck Regulator
For operating duty cycles less than the maximum duty
cycle of 75%, the OCP circuit still samples current for
typically 40ns, but starts sampling 40 ns after the rising
edge of PWMSet. Thus, for low duty cycle operation, the
inductor current is sensed close to the valley. This allows a
longer delay after the falling edge of the switch node, than
the corresponding delay for an over‐current sensing
scheme which samples the current at the peak of the
inductor current. This longer delay serves to filter out any
noise on the switch node and hence on the OCSet pin,
making this method more immune to false tripping.
THERMAL SHUTDOWN
Temperature sensing is provided inside iP1827.
The trip threshold is typically set to 145
trip threshold is exceeded, thermal shutdown turns
off both MOSFETs and discharges the soft start capacitor.
Automatic restart is initiated when the sensed
temperature drops within the operating range. There
is a 20
TRIMMABLE RISING EDGE DEADBAND
The iP1827 has a rising edge deadband that is post‐
package trimmable. It is typically trimmed to 5ns‐10ns
which is an optimal range to minimize switching transition
loss and at the same time, prevent cross conduction.
REMOTE VOLTAGE SENSING
True differential remote sensing in the feedback loop is
critical to high current applications where the output
voltage across the load may differ from the output voltage
measured locally across an output capacitor at the output
inductor, and to applications that require die voltage
sensing.
The Vosp and Vosm pins of the iP1827 form the inputs to
a remote sense differential amplifier with high speed, low
input offset (post‐package trimmed to +/‐3mV) and low
input bias current which ensure accurate voltage sensing
and fast transient response in such applications.
It should be noted, however, that the output Voso of the
difference amplifier also forms the input toa power good
comparator and overvoltage comparator, both referenced
to an upper threshold of 0.7V as discussed in the next
section. Hence, in applications where Vo > 0.6V, it is
necessary to use a resistive divider network after Vo to
attenuate the sensed output voltage signal between the
remote Vo and the remote ground to 0.6V, which is then
applied between Vosp and Vosm.
o
C hysteresis in the thermal shutdown threshold.
o
C. When the
iP1827
97599