LM5007SD/NOPB National Semiconductor, LM5007SD/NOPB Datasheet - Page 3

• Manufacturer Part Number: LM5007SD/NOPB
• Description: IC BUCK ADJ .5A 8LLP
• Manufacturer: National Semiconductor
• Type: Step-Down (Buck)r

Specifications of LM5007SD/NOPB

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 2.5 ~ 73 V
• Current - Output: 500mA
• Frequency - Switching: 800kHz
• Voltage - Input: 9 ~ 75 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-LLP
• For Use With: LM5007SD-EVAL - EVALUATION BOARD FOR LM5007SDLM5007EVAL - EVALUATION BOARD FOR LM5007
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: LM5007SD; LM5007SDTR

Pin Descriptions
Pin
1
2
3
4
5
6
7
8
-
Name
BST
RTN
R
Vcc
SW
R
Vin
FB
EP
ON
CL
Switching Node
Boost Boot–strap capacitor input
Current Limit OFF time programming pin
Toff = 10
Circuit Ground
Feedback Signal from Regulated Output
On time set pin
Ton = 1.42 x 10
Output from the internal high voltage bias regulator.
V
Input supply voltage
Exposed PAD, underside of the LLP package
option
CC
is nominally regulated to 7 Volts
-5
/ (0.59 + (FB / 7.22 x 10
-10
R
Description
ON
/ Vin
− 6
x R
3
CL
))
Power switching node. Connect to the LC output filter.
An external capacitor is required between the BST
and the SW pins. A 0.01uF ceramic capacitor is
recommended. An internal diode between Vcc and
BST completes the Buck gate drive bias network.
A resistor between this pin and RTN determines the
variation of off time, along with the FB pin voltage, per
cycle while in current limit. The off time is preset to
17uS if FB =0V and decreases as the FB pin voltage
increases.
This pin is connected to the inverting input of the
internal regulation comparator. The regulation
threshold is 2.5V.
A resistor between this pin and Vin sets the switch on
time as a function of Vin. The minimum recommended
on time is 300ns at the maximum input voltage.
If an auxiliary voltage is available to raise the voltage
on this pin, above the regulation setpoint (7V), the
internal series pass regulator will shutdown, reducing
the IC power dissipation. Do not exceed 14V. This
output provides gate drive power for the internal Buck
switch. An internal diode is provided between this pin
and the BST pin. A local 0.1uF decoupling capacitor
is recommended. Series pass regulator is current
limited to 10mA.
Recommended operating range: 9V to 75V.
Internally bonded to the die substrate. Connect to
GND potential for low thermal impedance.
Application Information
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