LMZ14203DEMO/NOPB National Semiconductor, LMZ14203DEMO/NOPB Datasheet - Page 3

• Manufacturer Part Number: LMZ14203DEMO/NOPB
• Description: BOARD DEV PWR MODULE LMZ14203
• Manufacturer: National Semiconductor
• Series: SIMPLE SWITCHER®r

Specifications of LMZ14203DEMO/NOPB

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 3.3V
• Current - Output: 3A
• Voltage - Input: 6 ~ 42 V
• Regulator Topology: Buck
• Frequency - Switching: Up to 1MHz
• Board Type: Fully Populated
• Utilized Ic / Part: LMZ14203
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Other names: LMZ14203DEMO

Demo Board Bill of Materials
Demo Board Hookup
VOUT Connect the load to VOUT and one of the GND posts.
The module can source up to a 3A load current.
VIN : Connect Vin to a positive voltage in the 8 to 42V range.
Connect the negative terminal of the source supply to one of
the posts labeled GND.
En: The Enable input post is configured for direct connection
to the Vin post. The on-board resistive voltage divider is cho-
sen such that when connected to 42V that the enable input at
pin 3 of the module will not exceed 6.5V. With the chosen
resistor values this results in an under voltage lockout level of
8 V input. The top enable resistor is RENT (aka REN1) and
the bottom enable resistor is RENB (aka REN2). The bottom
enable resistor may have a location for a shunt zener clamp
(Labeled D1 OPT in the silkscreen - Included only in the later
revisions of the assembly.)
Ref Des
RON
RENT
RENB
RFBT
RFBB
CFF
CSS
CIN1
CO1
CO2
U1
Alternate resistor values for alternative output voltages
VOUT
6
5
3.3
2.5
1.8
1.5
1.2
0.8
Description
61.9 kohm 1%
resistor
68.1 kohm 1%
resistor
11.8 kohm 1%
resistor
3.32 kohm 1%
resistor
1.07 kohm 1%
resistor
0.022 uF 50V X7R
ceramic capacitor
0.022 uF 50V X7R
ceramic capacitor
10 uF 50V X5R
ceramic capacitor
1.0 uF 50V X7R
ceramic capacitor
100 uF 6.3V X5R
ceramic capacitor
LMZ14203
SIMPLE
SWITCHER
Power Module
RFBT
2.49k
5.62k
3.32k
2.26k
1.87k
1.00k
4.22k
0.0K
3
Case
603
603
603
603
603
603
603
1210
1206
1210
TO-
PMOD
RFBB
3.83k
1.07k
1.07k
1.07k
1.50k
1.13k
8.45k
39.2k
Quiescent current: If the Enable post is disconnected, the
module will be disabled and about 20 uA of supply current will
flow from Vin to ground while in the disabled mode. With the
enable input connected to Vin via the 68.1K/11.8K divider
there will be about 1.5 mA of no-load quiescent current into
the Vin input. Additional current flows into the enable divider
string.
Demo Board Passive Components
Soft-start capacitor The soft-start capacitor controls the rise
time of the output voltage when power is first applied and fol-
lowing the clearing of a fault mode.
Feedback dividerRegulator output voltage is programmed
though the selection of the two resistors, RFBT ( aka RFB1)
and RFB (aka RFB2) A feed forward capacitor (CFF) is lo-
cated in parallel with the upper feedback divider resistor. This
capacitor improves the step response to abrupt changes in
Manufacturer
Part Number
UMK325BJ106M
M-T
UMK316B7105KL
-T
JMK325BJ107M
M-T
LMZ14203TZ-
ADJ
RON
124k
100k
61.9k
47.5k
32.4k
28.0k
22.6k
24.9k
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