Add buttons, relays, or sensors to an ESP8266 (which has limited GPIO) without extra analog muxes.

Official datasheets for the HIGHWAY09A are available through several professional electronic databases and distributors: Jotrin Electronics

| DE | RE | D | A – B Output | Receiver (R Pin) | |----|-----|-----|----------------|------------------| | 1 | 0 | 1 | Logic 1 (A > B)| Idle (disabled) | | 1 | 0 | 0 | Logic 0 (A < B)| Idle (disabled) | | 0 | 1 | X | High-Z (tri-state) | Differential A-B > -200mV → R = 1 A-B < -200mV → R = 0 Open/shorted bus → R = 1 (fail-safe) |

: Signal processing and control for automation systems . Functional Features :

| Marking seen | Real part | Function | |--------------|-----------|----------| | HA09A | HA17393A | Dual comparator | | 09A (SOT-23) | Often a 2.5V shunt regulator (TL431 equivalent) | Voltage reference | | A09 (SOT-23) | 2N7002 (MOSFET) or BSS84 | Small-signal MOSFET | | 09A (SOP-8) | LM339A (quad comparator) | Comparator |

When integrating the HIGHWAY09A, engineers should prioritize the following: HIGHWAY09A Holtek | | Xecor

Highway09a Ic Datasheet -

Add buttons, relays, or sensors to an ESP8266 (which has limited GPIO) without extra analog muxes.

Official datasheets for the HIGHWAY09A are available through several professional electronic databases and distributors: Jotrin Electronics highway09a ic datasheet

| DE | RE | D | A – B Output | Receiver (R Pin) | |----|-----|-----|----------------|------------------| | 1 | 0 | 1 | Logic 1 (A > B)| Idle (disabled) | | 1 | 0 | 0 | Logic 0 (A < B)| Idle (disabled) | | 0 | 1 | X | High-Z (tri-state) | Differential A-B > -200mV → R = 1 A-B < -200mV → R = 0 Open/shorted bus → R = 1 (fail-safe) | Add buttons, relays, or sensors to an ESP8266

: Signal processing and control for automation systems . Functional Features : highway09a ic datasheet

| Marking seen | Real part | Function | |--------------|-----------|----------| | HA09A | HA17393A | Dual comparator | | 09A (SOT-23) | Often a 2.5V shunt regulator (TL431 equivalent) | Voltage reference | | A09 (SOT-23) | 2N7002 (MOSFET) or BSS84 | Small-signal MOSFET | | 09A (SOP-8) | LM339A (quad comparator) | Comparator |

When integrating the HIGHWAY09A, engineers should prioritize the following: HIGHWAY09A Holtek | | Xecor