LT3755IMSE-1#PBF Linear Technology, LT3755IMSE-1#PBF Datasheet - Page 7

• Manufacturer Part Number: LT3755IMSE-1#PBF
• Description: IC LED DRVR HP CONS CURR 16-MSOP
• Manufacturer: Linear Technology
• Type: High Power, Constant Currentr

Specifications of LT3755IMSE-1#PBF

• Constant Current: Yes
• Constant Voltage: Yes
• Topology: Flyback, Low Side, PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: No
• Type - Primary: Automotive
• Type - Secondary: White LED
• Frequency: 100kHz ~ 1MHz
• Voltage - Supply: 4.5 V ~ 40 V
• Voltage - Output: 75V
• Mounting Type: Surface Mount
• Package / Case: 16-MSOP Exposed Pad
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 1A
• Internal Switch(s): Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Efficiency: -

Typical perForMance characTerisTics
pin FuncTions
PWMOUT (Pin 1/Pin 11): Buffered Version of PWM Signal
for Driving LED Load Disconnect NMOS or Level Shift.
This pin also serves in a protection function for the FB
overvoltage condition—will toggle if the FB input is greater
than the FB regulation voltage (V
The PWMOUT pin is driven from INTV
gate cut-off voltage higher than 1V is recommended.
FB (Pin 2/Pin 12): Voltage Loop Feedback Pin. FB is
intended for constant-voltage regulation or for LED protec-
tion/open LED detection. The internal transconductance
amplifier with output VC will regulate FB to 1.25V (nominal)
through the DC/DC converter. If the FB input is regulating
the loop, the OPENLED pull-down is asserted. This ac-
tion may signal an open LED fault. If FB is driven above
the FB threshold (by an external power supply spike, for
example), the OPENLED pull-down will be de-asserted and
the PWMOUT pin will be driven low to protect the LEDs
from an overcurrent event. Do not leave the FB pin open.
If not used, connect to GND.
40
30
20
10
0
0
ISP/ISN Input Bias Current
vs CTRL Voltage
0.5
(MSOP/QFN)
CTRL (V)
1
FB
ISP
ISN
) plus 60mV (typical).
CC
1.5
. Use of a FET with
37551 G19
2
ISN (Pin 3/Pin 13): Connection Point for the Negative
Terminal of the Current Feedback Resistor. If ISN is greater
than 2.9V, the LED current can be programmed by I
100mV/R
(10 • R
cally 25µA. Below 3V, ISN is an input to the short-circuit
protection feature that forces GATE to 0V if ISP exceeds
ISN by more than 150mV (typ).
ISP (Pin 4/Pin 14): Connection Point for the Positive
Terminal of the Current Feedback Resistor. Input bias
current is dependent upon CTRL pin voltage as shown
in the TPC. ISP is an input to the short-circuit protection
feature when ISN is less than 3V.
VC (Pin 5/Pin 15): Transconductance Error Amplifier
Output Pin Used to Stabilize the Voltage Loop with an RC
Network. This pin is high impedance when PWM is low, a
feature that stores the demand current state variable for
the next PWM high transition. Connect a capacitor between
this pin and GND; a resistor in series with the capacitor is
recommended for fast transient response.
LT3755/LT3755-1/LT3755-2
–0.5
–1.0
–2.5
–1.5
–2.0
LED
0
LED
0
INTV
vs Current, Temperature
) when V
V
T
IN
A
when V
T
= 7V
= 25°C, unless otherwise noted.
A
CC
5
= 25°C
Dropout Voltage
T
A
LDO CURRENT (mA)
10
CTRL
= 125°C
CTRL
T
A
= 150°C
15
> 1.2V or I
≤ 1V. Input bias current is typi-
T
A
= –45°C
20
LED
25
37551 G20
= (V
30
CTRL
–100mV)/
LED
37551fd

=