LM5070MTC-50 National Semiconductor, LM5070MTC-50 Datasheet - Page 3

• Manufacturer Part Number: LM5070MTC-50
• Description: IC,SMPS CONTROLLER,CURRENT-MODE,TSSOP,16PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LM5070MTC-50

• Rohs Compliant: NO
• Operating Temperature (max): 125C
• Operating Temperature (min): -40C
• Pin Count: 16
• Mounting: Surface Mount
• Package Type: TSSOP
• Case Length: 5mm
• Case Height: 0.9mm
• Screening Level: Automotive
• Lead Free Status / Rohs Status: Not Compliant

Pin
10
11
12
13
14
15
16
—
Pin Descriptions
1
2
3
4
5
6
7
8
9
RT / SYNC Oscillator timing resistor pin and
UVLORTN Return for the external UVLO resistors.
RCLASS
COMP
Name
UVLO
ARTN
RCLP
RSIG
RTN
OUT
V
V
V
CS
SS
EP
FB
EE
CC
IN
System high potential input.
Signature resistor pin.
Classification resistor pin.
Line under-voltage lockout.
Current limit programming pin.
System low potential input.
System return for the PWM converter.
Output of the PWM controller.
Output of the internal high voltage series
pass regulator. Regulated output voltage
is nominally 7.8V.
Feedback signal.
The output of the error amplifier and
input to the Pulse Width Modulator.
Current sense input.
synchronization input.
Soft-start input.
Analog PWM supply return.
Exposed PAD, underside of the LLP
package option.
Description
The diode “OR” of several lines entering the PD, it is the more
positive input potential.
Connect a 25kΩ signature resistor from V
detection.
Connect the classification programming resistor from this pin to
V
An external resistor divider from V
shutdown levels with a 2.00V threshold at the UVLO pin.
Hysteresis is set by a switched internal 10uA current source that
forces additional current into the resistor divider.
Connect the bottom resistor of the resistor divider between the
UVLO pin and this pin.
Programs the inrush current limit for the device. If left open, the
inrush current limit will default to 400mA max.
Diode “OR’d” to the RJ45 connector and PSE’s –48V supply, it is
the more negative input potential.
The drain of the internal current limiting power MOSFET which
connects V
DC-DC converter gate driver output with 800mA peak sink current
capability.
When the auxiliary transformer winding (if used) raises the voltage
on this pin above the regulation set point, the internal series pass
regulator will shutdown, reducing the controller power dissipation.
Inverting input of the internal error amplifier. The non-inverting
input is internally connected to a 1.25V reference.
COMP pull-up is provided by an internal 5K resistor which may be
used to bias an opto-coupler transistor.
Current sense input for current mode control and over-current
protection. Current limiting is accomplished using a dedicated
current sense comparator. If the CS pin voltage exceeds 0.5V the
OUT pin switches low for cycle-by-cycle current limiting. CS is held
low for 50ns after OUT switches high to blank leading edge current
spikes.
An external resistor connected from RT to ARTN sets the oscillator
frequency. This pin will also accept narrow ac-coupled
synchronization pulses from an external clock.
An external capacitor and an internal 10uA current source set the
soft-start ramp rate.
RTN for sensitive analog circuitry including the SMPS current limit
amplifier.
Internally bonded to the die substrate. Connect to V
low thermal impedance.
EE
3
.
EE
to the return path of the dc-dc converter.
Application Information
IN
to UVLORTN programs the
IN
to this pin for signature
EE
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potential for