LTC3803ES6-5#TRPBF Linear Technology, LTC3803ES6-5#TRPBF Datasheet - Page 11

• Manufacturer Part Number: LTC3803ES6-5#TRPBF
• Description: IC FLYBACK SYNC ADJ 1A TSOT23-6
• Manufacturer: Linear Technology
• Type: Flybackr

Specifications of LTC3803ES6-5#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: Adjustable
• Current - Output: 1A
• Frequency - Switching: 200kHz
• Voltage - Input: Adjustable
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-6, TSOT-6
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

APPLICATIONS INFORMATION
to duty cycle. This stabilizes the control loop against
subharmonic oscillation. The amount of reduction in the
current comparator threshold (ΔV
using the following equation:
Note: LTC3803-5 enforces 6.5% < Duty Cycle < 80%.
A good starting value for R
drop in current comparator threshold at 80% duty cycle.
Designs not needing slope compensation may replace
R
V
An internal shunt regulator allows the LTC3803-5 to be
powered through a single dropping resistor from V
V
closely decouples V
regulator can draw up to 25mA through the V
CC
CC
SL
ΔV
, in conjunction with a bypass capacitor, C
with a short circuit.
SHUNT REGULATOR
SENSE
Figure 3. Powering the LTC3803-5
Via the Internal Shunt Regulator
=
Duty Cycle – 6.5%
V
IN
73.5%
CC
R
VCC
C
to GND (see Figure 3). The shunt
VCC
SL
V
LTC3803-5
is 5.9k, which gives a 30mV
CC
GND
SENSE
• 5μA • R
38035 F03
) can be calculated
SL
CC
VCC
pin to
, that
IN
to
GND to drop enough voltage across R
V
enough such that the static power dissipation in R
acceptable, using the V
way to power the LTC3803-5.
EXTERNAL PREREGULATOR
The circuit in Figure 4 shows another way to power the
LTC3803-5. An external series preregulator consisting
of series pass transistor Q1, Zener diode D1, and bias
resistor R
enabling the LTC3803-5.
CC
to around 8.1V. For applications where V
B
brings V
R
100k
Figure 4. Powering the LTC3803-5
with an External Preregulator
B
D1
6.8V
75 V
8V TO
CC
Q1
MMBTA42
IN
CC
above the V
shunt regulator is the simplest
C
0.1μF
VCC
CC
V
LTC3803-5
LTC3803-5
CC
turn-on threshold,
GND
VCC
38035 F04
to regulate
IN
11
is low
VCC
38035fd
is