LYT0002/0004-0006
Topology
Basic Circuit Schematic
Key Features
FB
BP
S
D
+
High-Side
Buck –
Direct
•ꢀ Output referenced to input
•ꢀ Positive output (VO) with respect to -VIN
•ꢀ Step down – VO < VIN
LYTSwitch-0
VIN
Feedback
•ꢀ Low cost direct feedback ( 5% typ.)
PI-7043-053113
•ꢀ Output referenced to input
•ꢀ Negative output (VO) with respect to +VIN
•ꢀ Step down – VO < VIN
PI-7044-060313
IO
Low-Side
Buck –
Constant
Current LED
Driver;
+
•ꢀ Optocoupler feedback
•ꢀ Low-cost non-safety rated optocoupler
•ꢀ Optional Zener provides disconnected load
protection
•ꢀ Accuracy determined by VF variation of
optocoupler LED
VIN
VF
+
Optocoupler
Feedback
BP
D
FB
S
VF
R =
LYTSwitch-0
IO
•ꢀ Output referenced to input
•ꢀ Negative output (VO) with respect to +VIN
•ꢀ Step up/down – VO > VIN or VO < VIN
•ꢀ Low-cost direct feedback ( 5% typ.)
•ꢀ Fail-safe – output is not subjected to input voltage
if the internal power MOSFET fails
•ꢀ Ideal for driving LEDs – better accuracy and
temperature stability than low-side Buck constant
current LED driver
High-Side
Buck-Boost –
Constant
Current LED
Driver
RSENSE
FB
BP
S
IO
D
LYTSwitch-0
VIN
PI-7045-060313
+
•ꢀ Output referenced to input
•ꢀ Positive output (VO) with respect to -VIN
•ꢀ Step up – VO > VIN
•ꢀ Low-cost direct feedback ( 5% typ.)
•ꢀ Ideal for driving high-voltage LEDs string – good
accuracy and temperature stability
Low-Side
Boost –
Constant
Current LED
Driver
D
S
VIN
FB
BP
LYTSwitch-0
PI-7046-053113
•ꢀ Output referenced to input
+
•ꢀ Positive output (VO) with respect to -VIN
•ꢀ Step down – VO < VIN
•ꢀ Low-cost direct feedback ( 5% typ.)
•ꢀ Fail-safe – output is not subjected to input voltage
if the internal power MOSFET fails
Low-Side
Flyback –
Constant
Current LED
Driver
D
S
VIN
FB
BP
LYTSwitch-0
•ꢀ Ideal for driving very low voltage LEDs string –
•ꢀ good accuracy and temperature stability
PI-7047-060313
Table 2.
Common Circuit Configurations Using LYTSwitch-0 for Driving LEDs.
2
Rev. A 06/13
www.powerint.com
POWERINT [ Power Integrations ]
