LTM8023IV#PBF Linear Technology, LTM8023IV#PBF Datasheet - Page 8

• Manufacturer Part Number: LTM8023IV#PBF
• Description: IC BUCK SYNC ADJ 2A 50LGA
• Manufacturer: Linear Technology
• Series: µModuler
• Type: Point of Load (POL) Non-Isolatedr

Specifications of LTM8023IV#PBF

• Design Resources: LTM8023 Spice Model
• Output: 0.8 ~ 10 V
• Number Of Outputs: 1
• Power (watts): 20W
• Mounting Type: Surface Mount
• Voltage - Input: 3.6 ~ 36 V
• Package / Case: 50-LGA
• 1st Output: 0.8 ~ 10 VDC @ 2A
• Size / Dimension: 0.44" L x 0.35" W x 0.11" H (11.25mm x 9mm x 2.82mm)
• Power (watts) - Rated: 20W
• Operating Temperature: -40°C ~ 85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• 3rd Output: -
• 2nd Output: -

OPERATION
LTM8023
The LTM8023 is a standalone nonisolated step-down
switching DC/DC power supply. It can deliver up to 2A of
DC output current with only bulk external input and output
capacitors. This module provides a precisely regulated
output voltage programmable via one external resistor
from 0.8V
36V. Given that the LTM8023 is a step-down converter,
make sure that the input voltage is high enough to support
the desired output voltage and load current. A simplifi ed
Block Diagram is given on the previous page.
The LTM8023 contains a current mode controller, power
switching element, power inductor, power Schottky diode
and a modest amount of input and output capacitance.
The LTM8023 is a fi xed frequency PWM regulator. The
switching frequency is set by simply connecting the
appropriate resistor value from the R
An internal regulator provides power to the control cir-
cuitry. The bias regulator normally draws power from the
V
APPLICATIONS INFORMATION
For most applications, the design process is straight
forward, summarized as follows:
1. Look at Table 1 and fi nd the row that has the desired
2. Apply the recommended C
3. Connect BIAS as indicated.
While these component combinations have been tested for
proper operation, it is incumbent upon the user to verify
proper operation over the intended system’s line, load and
environmental conditions.
Capacitor Selection Considerations
The C
minimum recommended values for the associated oper-
ating conditions. Applying capacitor values below those
8
IN
input range and output voltage.
pin, but if the BIAS pin is connected to an external
IN
and C
DC
to 10V
OUT
DC
capacitor values in Table 1 are the
. The input voltage range is 3.6V to
IN
, C
OUT
, R
T
pin to GND.
ADJ
and R
T
values.
voltage higher than 2.8V, bias power will be drawn from
the external source (typically the regulated output voltage).
This improves effi ciency. The RUN/SS pin is used to place
the LTM8023 in shutdown, disconnecting the output and
reducing the input current to less than 1μA.
To further optimize effi ciency, the LTM8023 automatically
switches to Burst Mode operation in light load situations.
Between bursts, all circuitry associated with controlling the
output switch is shut down reducing the input supply cur-
rent to 50μA in a typical application. The oscillator reduces
the LTM8023’s operating frequency when the voltage at the
ADJ pin is low. This frequency foldback helps to control
the output current during start-up and overload.
The LTM8023 contains a power good comparator which
trips when the ADJ pin is at 92% of its regulated value.
The PG output is an open-collector transistor that is off
when the output is in regulation, allowing an external
resistor to pull the PG pin high. Power good is valid when
the LTM8023 is enabled and V
indicated in Table 1 is not recommended, and may result
in undesirable operation. Using larger values is generally
acceptable, and can yield improved dynamic response, if
it is necessary. Again, it is incumbent upon the user to
verify proper operation over the intended system’s line,
load and environmental conditions.
Ceramic capacitors are small, robust and have very low
ESR. However, not all ceramic capacitors are suitable.
X5R and X7R types are stable over temperature and ap-
plied voltage and give dependable service. Other types,
including Y5V and Z5U have very large temperature and
voltage coeffi cients of capacitance. In an application cir-
cuit they may have only a small fraction of their nominal
capacitance resulting in much higher output voltage ripple
than expected.
IN
is above 3.6V.
8023ff