Texas Instruments Evaluation Board for the LM25066I LM25066I-EVM/NOPB LM25066I-EVM/NOPB データシート
製品コード
LM25066I-EVM/NOPB
SNVS824C – JUNE 2012 – REVISED MARCH 2013
Pin Descriptions
Pin
Name
Description
Applications Information
No.
Pad
Exposed
Exposed pad of WQFN
No internal electrical connection. Solder to the ground plane to reduce thermal resistance.
Pad
package
1
ADR2
SMBUS address line 2
3 - state address line. Should be connected to GND, VDD, or left floating.
2
ADR1
SMBUS address line 1
3 - state address line. Should be connected to GND, VDD, or left floating.
3
ADR0
SMBUS address line 0
3 - state address line. Should be connected to GND, VDD, or left floating.
4
VDD
Internal sub-regulator
Internally sub-regulated 4.5V bias supply. Connect a 1 µF capacitor on this pin to ground
output
for bypassing.
5
CL
Current limit range
Connect this pin to GND to set the nominal over-current threshold at 25mV. Connecting
CL to VDD will set the over-current threshold to be 46mV.
CL to VDD will set the over-current threshold to be 46mV.
6
CB
Circuit breaker range
This pin sets the circuit breaker protection point in relation to the over-current trip point.
When connected to GND, this pin will set the circuit breaker point to be 1.8 times the
over-current threshold. Connecting this pin to VDD sets the circuit breaker trip point to be
3.6 times the over-current threshold.
When connected to GND, this pin will set the circuit breaker point to be 1.8 times the
over-current threshold. Connecting this pin to VDD sets the circuit breaker trip point to be
3.6 times the over-current threshold.
7
FB
Power Good feedback
An external resistor divider from OUT sets the output voltage at which the PGD pin
switches. The threshold at the pin is 1.167V. An internal 24 µA current source provides
hysteresis.
switches. The threshold at the pin is 1.167V. An internal 24 µA current source provides
hysteresis.
8
RETRY
Fault retry input
This pin configures the power up fault retry behavior. When this pin is grounded, the
device will continually try to engage power during a fault. If the pin is connected to VDD,
the device will latch off during a fault.
device will continually try to engage power during a fault. If the pin is connected to VDD,
the device will latch off during a fault.
9
TIMER
Timing capacitor
An external capacitor connected to this pin sets the insertion time delay, fault timeout
period and restart timing.
period and restart timing.
10
PWR
Power limit set
An external resistor connected to this pin, in conjunction with the current sense resistor
(R
(R
S
), sets the maximum power dissipation allowed in the external series pass MOSFET.
11
PGD
Power Good indicator
An open drain output. This output is high when the voltage at the FB pin is above 1.167V
and the input supply is within its under-voltage and over-voltage thresholds. Connect via a
pullup resistor to the output rail (external MOSFET source) or any other voltage to be
monitored.
and the input supply is within its under-voltage and over-voltage thresholds. Connect via a
pullup resistor to the output rail (external MOSFET source) or any other voltage to be
monitored.
12
OUT
Output feedback
Connect to the output rail (external MOSFET source). Internally used to determine the
MOSFET V
MOSFET V
DS
voltage for power limiting, and to monitor the output voltage.
13
GATE
Gate drive output
Connect to the external MOSFET's gate.
14
SENSE
Current sense input
The voltage across the current sense resistor (R
S
) is measured from VIN to this pin. If the
voltage across R
S
reaches over-current threshold, the load current is limited and the fault
timer activates.
15
VIN
Positive supply input
A small ceramic bypass capacitor close to this pin is recommended to suppress transients
which occur when the load current is switched off.
which occur when the load current is switched off.
16
UVLO/EN
Under-voltage lockout
An external resistor divider from the system input voltage sets the under-voltage turn-on
threshold. An internal 23 µA current source provides hysteresis. The enable threshold at
the pin is 1.16V. This pin can also be used for remote shutdown control.
threshold. An internal 23 µA current source provides hysteresis. The enable threshold at
the pin is 1.16V. This pin can also be used for remote shutdown control.
17
OVLO
Over-voltage lockout
An external resistor divider from the system input voltage sets the over-voltage turn-off
threshold. An internal 23 µA current source provides hysteresis. The disable threshold at
the pin is 1.16V.
threshold. An internal 23 µA current source provides hysteresis. The disable threshold at
the pin is 1.16V.
18
GND
Circuit ground
19
SDA
SMBus data pin
Data pin for SMBus.
20
SCL
SMBus clock
Clock pin for SMBus.
21
SMBA
SMBus alert line
Alert pin for SMBus, active low.
22
VREF
Internal Reference
Internally generated precision 2.73V reference used for analog to digital conversion.
Connect a 1 µF capacitor on this pin to ground for bypassing.
Connect a 1 µF capacitor on this pin to ground for bypassing.
23
DIODE
External diode
Connect this to a diode-configured NPN transistor for temperature monitoring.
24
VAUX
Auxiliary voltage input
Auxiliary pin allows voltage telemetry from an external source. Full scale input of 1.16V.
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.
during storage or handling to prevent electrostatic damage to the MOS gates.
Copyright © 2012–2013, Texas Instruments Incorporated
3
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