SPICE subcircuitBSS138 2-ch modulebss138_ls2
Level shifter 2-ch (BSS138, bidirectional)
Bidirectional logic level converter module with 2 channels: one BSS138 MOSFET and two 10 kΩ pull-ups per channel (NXP AN10441). LV = low supply (e.g. 3.3 V), HV = high supply (e.g. 5 V); for I²C, UART, slow SPI. Rise time set by the 10 kΩ pull-ups and the line capacitance.
Key data
- Category
- Modules
- Simulation model
- SPICE subcircuit
- Manufacturer part number
- BSS138 2-ch module
- Reference prefix
- U
- Pins
- 7
- Land pattern
- PinHeader_1x08_P2.54mm_Vertical
Notes
- Use it for I²C, UART and slow SPI (up to about 1 MHz with the 10 kΩ pull-ups). Both sides need their supply connected.
Simulation model
The part is a small SPICE netlist (below), solved by the analog engine together with the rest of the circuit. Pin ids are the node names, {braces} are parameters.
SPICE netlist
RL1 LV LV1 10k
RH1 HV HV1 10k
M1 HV1 LV LV1 LV1 NMOS_BSS138
D1 LV1 HV1 DBSS138
RL2 LV LV2 10k
RH2 HV HV2 10k
M2 HV2 LV LV2 LV2 NMOS_BSS138
D2 LV2 HV2 DBSS138.model NMOS_BSS138 NMOS(VTO=1.3 KP=0.052 LAMBDA=0.01 CGS=21p CGD=6p)
.model DBSS138 D(IS=1e-12 N=1 RS=1.61 BV=50 IBV=10u)Pins 7
| Pin | Name | Use |
|---|---|---|
| LV | LVSupply pin | Low-voltage supply (e.g. 3.3 V): gate of the MOSFETs and LV pull-ups |
| LV1 | LV1I/O pin · pulled up on the board | Signal on the low-voltage side (to the 3.3 V device), 10 kΩ pull-up to LV |
| LV2 | LV2I/O pin · pulled up on the board | Signal on the low-voltage side (to the 3.3 V device), 10 kΩ pull-up to LV |
| HV | HVSupply pin | High-voltage supply (e.g. 5 V): HV pull-ups |
| HV1 | HV1I/O pin · pulled up on the board | Signal on the high-voltage side (to the 5 V device), 10 kΩ pull-up to HV |
| HV2 | HV2I/O pin · pulled up on the board | Signal on the high-voltage side (to the 5 V device), 10 kΩ pull-up to HV |
| GND | GNDGround pin | Ground |
PCB
Verified land pattern
PinHeader_1x08_P2.54mm_Vertical| Package | Land pattern | Status | Source |
|---|---|---|---|
| module | PinHeader_1x08_P2.54mm_Vertical | Verified land pattern | module on a 2.54 mm pin header, LV1, LV2, LV, GND, HV1, HV2, HV, GND (SparkFun BOB-12009 order: compare with your module) |