component
MC34018M
Public Made by Adomby adom
HGSEMI Audio Amplifiers, SOP-28-300mil. Datasheet-verified pinout, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownMC34018M
HGSEMI · Audio Amplifiers · SOP-28-300mil
MC34018M from HGSEMI, in a SOP-28-300mil. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | RR | passive | External ground resistor provides reference current for transmit and receive attenuators. |
| 2 | RTX | passive | External ground resistor determines transmit attenuator normal gain; transmit channel gain inversely proportional to resistance. |
| 3 | TXI | input | Transmit attenuator input with nominal input impedance of 5 kΩ. |
| 4 | TXO | output | Transmit attenuator output drives transmit level detector input and external telephone line circuit. |
| 5 | TLI | input | Transmit level detector input with external AC-coupled resistor establishing detection threshold; reduced resistance increases channel sensitivity. |
| 6 | TLO | output | Transmit level detector output with external resistor and capacitor determining comparator timing constants. |
| 7 | RLI | input | Receive level detector input with external AC-coupled resistor establishing detection threshold; reduced resistance increases channel sensitivity. |
| 8 | RLO | output | Receive level detector output with external resistor and capacitor determining comparator timing constants. |
| 9 | MCI | input | Microphone amplifier input with nominal impedance of 10 kΩ and DC bias voltage equal to VB. |
| 10 | MCO | output | Microphone amplifier output with internal gain fixed at 34 dB. |
| 11 | CP1 | passive | Connected to power supply VCC with external parallel RC network to maintain background noise level reference for comparison against CP2 signal. |
| 12 | CP2 | input | Voice signal peak detection input compared against background noise level held at CP1. |
| 13 | XDI | input | Transmit detector system input with microphone amplifier output AC-coupled to establish transmit detection. |
| 14 | SKG | power_in | Speaker amplifier output stage ground return; voltage difference between SKG and pin 22 shall not exceed 10 mV. |
| 15 | SKO | output | Speaker amplifier output capable of providing 100 mA source current to AC-coupled speaker load; internal gain 34 dB. |
| 16 | V+ | power_in | DC power supply input requiring 6 V to 11 V (typical 7.5 V) at 7 mA current. |
| 17 | AGC | passive | Connected with external capacitor to VB for temperature stabilization of speaker amplifier gain control loop and response time adjustment. |
| 18 | CS | input | Chip select input; logic low (<0.7 V) enables VCC regulation, logic high (>1.6 V) puts circuit in standby mode with 0.5 mA current; typical input impedance 400 kΩ. |
| 19 | SKI | input | Speaker amplifier input with typical impedance of 20 kΩ. |
| 20 | VCC | power_out | Regulated 5.4 V voltage output supplying all circuit sections except speaker amplifier output stage; maximum external load current 3 mA. |
| 21 | VB | power_out | Voltage output equal to VCC/2 serving as analog ground reference for speaker phone system; maximum external load current 1.5 mA. |
| 22 | GND | power_in | Ground return for all circuit sections except speaker amplifier output stage. |
| 23 | XDC | output | Transmit detector output with external RC network maintaining transmit mode; transitions to standby when voltage drops to ground. |
| 24 | VLC | input | Volume control input with external potentiometer for receive mode gain adjustment; voltage range 0.55×VB to VB. |
| 25 | ACF | passive | Attenuator control filter input connected with external capacitor to reduce noise transients and control attenuation switching. |
| 26 | RXO | output | Receive attenuator output AC-coupled to speaker amplifier input. |
| 27 | RXI | input | Receive attenuator input with typical impedance of 5 kΩ. |
| 28 | RRX | passive | External ground resistor determines receive attenuator normal gain; receive channel gain inversely proportional to resistance. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | HGSEMI |
| Package | SOP-28-300mil |
| Category | Amplifiers/Comparators |
| Pins | 28 |
CAD (KiCad official)
- Symbol:
MC34018M - Footprint:
Package_SO:SOP-28_8.4x18.16mm_P1.27mm - 3D model: SOP-28-300mil (KiCad packages3D, STEP)
- 3D model files:
mc34018m-etched.step/mc34018m-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mc34018m.step/mc34018m.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: HGSEMI datasheet (9 pp, sha256
25fffe7e4cb77c2d, retrieved 2026-09-22, tier: lcsc) - Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- Extractor: parts-factory
2.0.0/extract_pins 0.2, primaryclaude-haiku-4-5-20251001(text), consensusclaude-sonnet-4-6(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).