LNK3202/3204-6
Topology
Basic Circuit Schematic
Key Features
1. Output referenced to input
High-Side
Buck –
Direct
Feedback
2. Positive output (VO) with respect to -VIN
3. Step down – VO < VIN
4. Low cost direct feedback (±10% typ.)
5. Requires an output load to maintain regulation
FB
BP/M
S
D
+
VIN
+
LinkSwitch-TN2
VO
PI-7843-031616
1. Output referenced to input
2. Positive output (VO) with respect to -VIN
3. Step down – VO < VIN
FB
BP/M
S
High-Side
Buck –
D
+
+
4. Optocoupler feedback
LinkSwitch-TN2
Optocoupler
Feedback
- Accuracy only limited by reference choice
- Low cost non-safety rated optocoupler
- No pre-load required
VIN
VO
5. Minimum no-load consumption
PI-7844-031616
+
+
Low-Side
Buck –
LinkSwitch-TN2
VIN
VO
Optocoupler
Feedback
BP/M
S
FB
1. Output referenced to input
2. Negative output (VO) with respect to +VIN
3. Step down – VO < VIN
D
PI-7845-031616
4. Optocoupler feedback
+
IO
- Accuracy only limited by reference choice
- Low cost non-safety rated optocoupler
- No pre-load required
Low-Side
Buck –
LinkSwitch-TN2
VF
VIN
+
- Ideal for driving LEDs
Constant
Current LED
Driver
FB
BP/M
S
D
VF
PI-7846-031616
R =
IO
High-Side
Buck-Boost –
Direct
FB
BP/M
S
D
+
1. Output referenced to input
Feedback
LinkSwitch-TN2
VIN
VO
2. Negative output (VO) with respect to +VIN
3. Step up/down – VO > VIN orVO < VIN
4. Low cost direct feedback (±10% typ.)
5. Fail-safe – output is not subjected to input
voltage if the internal power MOSFET fails
6. Ideal for driving LEDs – better accuracy and
temperature stability than low-side buck
constant current LED driver
+
PI-7847-031616
2 V
300 Ω
RSENSE
=
IO
2 kΩ
High-Side
Buck-Boost –
Constant
Current LED
Driver
RSENSE
FB
BP/M
S
IO
D
+
7. Requires an output load to maintain regulation
LinkSwitch-TN2
VIN
10 µF
50 V
100 nF
PI-7849-031616
Table 3.
Common Circuit Configurations using LinkSwitch-TN2. (continued on next page)
7
Rev. F 01/17
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