Datasheet

1
2
3
4 5
6
7
8
SW
BST
RCL
FB
RTN
RON/SD
VCC
VIN
LM5009
SNVS402G –FEBRUARY 2006–REVISED FEBRUARY 2013 www.ti.com
Connection Diagram
Figure 2. 8-Lead VSSOP or WSON
Pin Functions
Table 1. Pin Descriptions
Pin Name Description Application Information
1 SW Switching output Power switching output. Connect to the inductor, re-circulating diode, and bootstrap
capacitor.
2 BST Boost Pin An external capacitor is required between the BST and the SW pins. A 0.022 µF
ceramic capacitor is recommended. An internal diode charges the capacitor from
V
CC
.
3 RCL Current Limit off-time set A resistor between this pin and RTN sets the off-time when current limit is detected.
pin The off-time is preset to 35µs if FB = 0V.
4 RTN Ground pin Ground for the entire circuit.
5 FB Feedback input from This pin is connected to the inverting input of the internal regulation comparator. The
Regulated Output regulation threshold is 2.5V.
6 RON/SD On-time set pin A resistor between this pin and VIN sets the switch on-time as a function of V
IN
. The
minimum recommended on-time is 250ns at the maximum input voltage. This pin
can be used for remote shutdown.
7 VCC Output from the internal If an auxiliary voltage is available to raise the voltage on this pin above the
high voltage startup regulation set point (7V), the internal series pass regulator will shutdown, reducing
regulator. Regulated at the IC power dissipation. Do not exceed 14V. This voltage provides gate drive
7.0V. power for the internal Buck switch. An internal diode is provided between this pin
and the BST pin. A local 0.1µF decoupling capacitor is required.
8 VIN Input voltage Recommended operating range: 9.5V to 95V.
EP Exposed pad Exposed metal pad on the underside of the device. It is recommended to connect
(WSON package only) this to the PC board ground plane to aid in heat dissipation.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings
(1)
V
IN
to RTN -0.3V to 100V
BST to RTN -0.3V to 114V
SW to RTN (Steady State) -1V
ESD Rating, Human Body Model
(2)
2kV
BST to VCC 100V
BST to SW 14V
VCC to RTN 14V
All Other Inputs to RTN -0.3 to 7V
Storage Temperature Range -65°C to +150°C
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is intended to be functional. For specifications and test conditions, see the Electrical Characteristics.
(2) The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
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