Request Quote
(Ships tomorrow)
HMA121C Optoisolator Equivalent & Substitute Parts
Part Overview
The HMA121C is a 3750Vrms optoisolator with transistor output manufactured by onsemi in a 4-SMD package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The HMA121C provides single-channel isolation suitable for DC input applications with 80V maximum output voltage and 80mA output current capability.
Substiute Parts
Key Parameters
| Parameter | Value |
|---|---|
| Isolation Voltage | 3750Vrms |
| Number of Channels | 1 |
| Output Type | Transistor |
| Input Type | DC |
| Current Transfer Ratio (Min) | 100% @ 5mA |
| Current Transfer Ratio (Max) | 200% @ 5mA |
| Voltage - Output (Max) | 80V |
| Current - Output / Channel | 80mA |
| Vce Saturation (Max) | 400mV |
| Operating Temperature Range | -40°C ~ 100°C |
| Mounting Type | Surface Mount |
| Package / Case | 4-SMD, Gull Wing |
| Moisture Sensitivity Level (MSL) | 1 (Unlimited) |
Substitute Part Grouping Explanation
Substitution for the HMA121C is determined by the following critical parameters:
- Isolation Voltage: All substitutes must maintain 3750Vrms isolation
- Output Type: Transistor output configuration required
- Input Type: DC input compatibility
- Number of Channels: Single channel
- Voltage - Output (Max): 80V maximum
- Current - Output / Channel: Minimum 50mA (HMA121C specifies 80mA)
- Mounting Type: Surface Mount
- Vce Saturation: Lower values indicate improved performance
Substitute parts are grouped by package type (4-SMD, 4-SOP, 4-SOIC, 4-Mini-Flat) and Current Transfer Ratio ranges. Parts with identical electrical specifications but different packaging or CTR grades are direct functional equivalents within their respective package families.
Parameter Comparison
| Part Number | Manufacturer | Isolation Voltage | CTR Min @ 5mA | CTR Max @ 5mA | Vout (Max) | Iout / Channel | Vce Sat (Max) | Temp Range | Package | Status |
|---|---|---|---|---|---|---|---|---|---|---|
| HMA121C | onsemi | 3750Vrms | 100% | 200% | 80V | 80mA | 400mV | -40°C ~ 100°C | 4-SMD | Obsolete |
| FODM121C | onsemi | 3750Vrms | 100% | 200% | 80V | 80mA | 400mV | -40°C ~ 110°C | 4-SMD | Active |
| EL357ND(TA)-G | Everlight Electronics | 3750Vrms | 300% | 600% | 80V | 50mA | 200mV | -55°C ~ 110°C | 4-SOP | Active |
| HCPL-181-000E | Broadcom Limited | 3750Vrms | 50% | 600% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-SOIC | Active |
| HCPL-181-00AE | Broadcom Limited | 3750Vrms | 80% | 160% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-Mini-Flat | Active |
| HCPL-181-00BE | Broadcom Limited | 3750Vrms | 130% | 260% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-Mini-Flat | Active |
| HCPL-181-00CE | Broadcom Limited | 3750Vrms | 200% | 400% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-Mini-Flat | Active |
| HCPL-181-00DE | Broadcom Limited | 3750Vrms | 300% | 600% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-Mini-Flat | Active |
| HCPL-181-06BE | Broadcom Limited | 3750Vrms | 130% | 260% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-Mini-Flat | Active |
| HCPL-181-06DE | Broadcom Limited | 3750Vrms | 300% | 600% | 80V | 50mA | 200mV | -55°C ~ 100°C | 4-Mini-Flat | Active |
| LTV-356T | Lite-On Inc. | 3750Vrms | 50% | 600% | 80V | 50mA | 200mV | -55°C ~ 110°C | 4-SOP | Active |
Engineering Selection Recommendations
Direct Equivalent (Same Package, Active Status): FODM121C is the primary direct replacement for HMA121C. Both are onsemi products in 4-SMD packaging with identical electrical specifications. FODM121C extends the operating temperature range to 110°C and carries Active product status with RoHS3 compliance.
Package-Specific Alternatives:
For 4-Mini-Flat package applications, the Broadcom HCPL-181 series offers multiple Current Transfer Ratio grades. HCPL-181-00BE and HCPL-181-06BE match the HMA121C CTR range (130-260% @ 5mA). HCPL-181-00CE and HCPL-181-06DE provide higher CTR (200-600% @ 5mA) for applications requiring faster switching response. All HCPL-181 variants feature improved Vce saturation (200mV vs. 400mV) and extended temperature range (-55°C to 100°C).
For 4-SOP package requirements, EL357ND(TA)-G (Everlight) and LTV-356T (Lite-On) both provide 3750Vrms isolation with 50mA output current. EL357ND(TA)-G specifies 300-600% CTR with -55°C to 110°C operating range. LTV-356T offers wider CTR range (50-600%) and -55°C to 110°C temperature coverage.
For 4-SOIC package, HCPL-181-000E provides the widest CTR specification (50-600%) with -55°C to 100°C operating range.
All substitute parts maintain RoHS3 compliance and MSL 1 rating. Product status is Active for all listed substitutes.
Frequently Asked Questions (FAQ)
Q: Can FODM121C directly replace HMA121C without PCB layout changes? A: Yes. FODM121C is electrically identical to HMA121C and uses the same 4-SMD package with Gull Wing leads. No layout modifications are required.
Q: What is the difference between HCPL-181-00BE and HCPL-181-00CE? A: Both use 4-Mini-Flat packaging and share identical electrical specifications except Current Transfer Ratio. HCPL-181-00BE specifies 130-260% CTR @ 5mA, while HCPL-181-00CE specifies 200-400% CTR @ 5mA. Selection depends on required switching speed and input current drive capability.
Q: Why do some substitutes specify 50mA output current instead of 80mA? A: EL357ND(TA)-G, HCPL-181 series, and LTV-356T are rated for 50mA maximum output current per channel. These parts are suitable for applications requiring up to 50mA. For designs requiring the full 80mA output current of HMA121C, FODM121C is the appropriate choice.
Q: Are all listed substitutes RoHS3 compliant? A: Yes. All substitute parts carry RoHS3 compliance certification. HMA121C is listed as REACH Unaffected; all active substitutes maintain REACH Unaffected status.
Q: What is the temperature operating range difference between HMA121C and its substitutes? A: HMA121C operates from -40°C to 100°C. FODM121C extends the upper limit to 110°C. Broadcom HCPL-181 series and Lite-On LTV-356T extend the lower limit to -55°C and upper limit to 100-110°C. Everlight EL357ND(TA)-G covers -55°C to 110°C, the widest range.
Q: Can I use HCPL-181-000E in place of HMA121C? A: HCPL-181-000E is electrically compatible but uses 4-SOIC packaging instead of 4-SMD. PCB layout and footprint modifications are required. The part provides superior performance with 200mV Vce saturation and extended temperature range (-55°C to 100°C).
Q: What does Current Transfer Ratio (CTR) represent? A: CTR is the ratio of output collector current to input LED current, expressed as a percentage at specified input current (5mA for these parts). Higher CTR indicates greater output current for the same input drive, enabling faster switching or lower input current requirements.
Alternative Parts
SJ6012L2TP
Littelfuse Inc.
6 Alternative Parts
JMK107BBJ476MA-RE
Taiyo Yuden
10 Alternative Parts
GMK107BBJ475MA-T
Taiyo Yuden
5 Alternative Parts
SJ6020N2ARP
Littelfuse Inc.
3 Alternative Parts
SJ6025R2ATP
Littelfuse Inc.
4 Alternative Parts
2474-05L
API Delevan Inc.
1 Alternative Parts
4590R-684K
API Delevan Inc.
1 Alternative Parts
CM6560R-334
API Delevan Inc.
1 Alternative Parts
CM6460-104
API Delevan Inc.
1 Alternative Parts
5526-12
API Delevan Inc.
1 Alternative Parts