LTC3806
Synchronous
Flyback DC/DC Controller
FEATURES
s
s
DESCRIPTIO
s
s
s
s
s
s
s
s
High Efficiency at Full Load
Better Cross Regulation Than Nonsynchronous
Converters (Multiple Outputs)
Soft-Start Minimizes Inrush Current
Current Mode Control Provides Excellent
Transient Response
High Maximum Duty Cycle: 89% Typical
鹵2%
Programmable Undervoltage Lockout Threshold
鹵1%
Internal Voltage Reference
Micropower Start-Up
Constant Frequency Operation (Never Audible)
3mm
脳
4mm 12-Pin DFN Package
The LTC
廬
3806 is a current mode synchronous flyback
controller that drives N-channel power MOSFETs and
requires very few external components. It is intended for
medium power applications where multiple outputs are
required. Synchronous rectification provides higher effi-
ciency and improved output cross regulation than
nonsynchronous converters.
The IC contains all the necessary control circuitry includ-
ing a 250kHz oscillator, precision undervoltage lockout
circuit with hysteresis, gate drivers for primary and syn-
chronous switches, current mode control circuitry and
soft-start circuitry.
Programmable soft-start reduces inrush currents. This
makes it easier to design compliant Power Over Ethernet
supplies.
Low start-up current reduces power dissipation in the
start-up resistor and reduces the size of the external start-
up capacitor.
The LTC3806 is available in a 12-pin, exposed pad DFN
package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
s
48V Telecom Supplies
12V/42V Automotive
24V Industrial
VoIP Phone
Power Over Ethernet
TYPICAL APPLICATIO
V
IN
36V TO 72V
R1
51k
R2
604k
C7
4.7碌F
LTC3806
RUN SENSE
R8
100鈩?/div>
I
TH
FB
V
IN
C1
100碌F
R3
26.7k
C2
1nF
R4
3.4k
INTV
CC
C3
4.7碌F
SS
G2
G1
GND
D1
T1
鈥?/div>
鈥?/div>
鈥?/div>
M1
M2
C4
0.47碌F
R5
0.056鈩?/div>
R7
12.4k
R6
21k
Figure 1. Multiple Output Flyback Converter for Telecom
3806f
U
V
OUT1
3.3V
V
OUT2
3A
2.5V
3A
M3
C5
470碌F
C6
470碌F
3806 F01
U
U
1
next
LTC3806EDE相關(guān)型號PDF文件下載
-
型號
版本
描述
廠商
下載
-
英文版
500mA, Low Voltage, Very Low Dropout Linear Regulator
LINER
-
英文版
300mA Micropower VLDO Linear Regulator
Linear
-
英文版
1.5A Low Input Voltage VLDO Linear Regulator
LINER
-
英文版
1.5A Low Input Voltage VLDO Linear Regulator
Linear
-
英文版
300mA VLDO Linear Regulator with Charge Pump Bias Generator
Linear
-
英文版
400mA Step-Up DC/DC Converter with Maximum Power Point Contr...
Linear
-
英文版
Auto-Polarity, Ultralow Voltage Step-Up Converter and Power ...
Linear
-
英文版
DC/DC CONVERTERl
LINER
-
英文版
100mA Low Noise, Regulated Charge Pump Step-Up Converters
Linear
-
英文版
100mA Ultralow Noise Charge Pump LED Supply with Output Curr...
Linear
-
英文版
Low Noise, High Efficiency Charge Pump for White LEDs
LINER
-
英文版
125mA Low Noise, High Efficiency Charge Pump for White LEDs
Linear
-
英文版
Linear Technology [Low Noise Regulated Charge Pump in 2 X 2...
LINER
-
英文版
Single Cell 350mA LED Driver
LINER
-
英文版
Multidisplay LED Controller
Linear
-
英文版
I2C Multidisplay LED Controller
LINER
-
英文版
I2C Multidisplay LED Controller
Linear
-
英文版
High Current Software Confi gurable Multidisplay LED Control...
Linear
-
英文版
MAIN/CAM LED Controller in 3mm × 3mm QFN
Linear
-
英文版
500mA Camera LED Charge Pump
LINER