772 Pseudo-PTAT cell based bandgap reference
772 : Pseudo-PTAT cell based bandgap reference
- Author: Istvan Kovacs
- Description: Simple bandgap reference voltage generator based on the pseudo-PTAT current generator with enable gated startup included.
- GitHub repository
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- Clock: 0 Hz
How it works
Simple bandgap reference voltage generator based on the pseudo-PTAT current generator with enable gated startup included.
Pind description
Input digital controls:
ui[0]: - enable to monitor "nout" on ua[0] ui[1]: - enable to monitor "nc1" on ua[0] ui[2]: - enable to monitor "vbgtop" on ua[0] ui[3]: - enable to monitor "vbgmid" on ua[0] ui[4]: - enable to monitor "vbgbot"" on ua[0] ui[5]: "enbgrbot" - enables the sartup circuit of the BGR on the BOTTOM side of the tile ui[6]: "enbgrmid" - enables the sartup circuit of the BGR on the MIDDLE side of the tile ui[7]: "enbgrtop" - enables the sartup circuit of the BGR on the TOP side of the tile
Outputs
uo[0]: "enbbgrtop" - monitor the inverted version of ui[7]
Analog pins
ua[0]: "VREF_TT" - outputs the internal nodes baed on the selected digital inputs ui[0..4]
How to test
When the 1.8V supply is applied the analog output ua[0]="VREF_TT" should provide a voltage level close to 1.2V with low temperature dependence if ui[6]='1 ui[3]='1. The ena signal controls the refrence startup circuit in case the circuit won't start up togle ena='1.
External hardware
Voltage measurement equipment is required to measure the output voltage.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | nout | enbbgrtop | |
| 1 | nc1 | ||
| 2 | vbgtop | ||
| 3 | vbgmid | ||
| 4 | vbgbot | ||
| 5 | enbgrbot | ||
| 6 | enbgrmid | ||
| 7 | enbgrtop |
Analog pins
ua | PCB Pin | Internal index | Description |
|---|---|---|---|
| 0 | B4 | 10 | VREF_TT |