Request Quote
(Ships tomorrow)
MAX921CSA-T Equivalent & Substitute Parts
Part Overview
The MAX921CSA-T is a comparator with integrated voltage reference manufactured by Analog Devices Inc./Maxim Integrated. This linear IC operates as a single-element comparator with CMOS and TTL output capability in an 8-SOIC surface mount package. The part is currently obsolete, which necessitates identification of functionally equivalent active alternatives for new designs and production continuity.
Substiute Parts
Key Parameters
| Parameter | MAX921CSA-T |
|---|---|
| Manufacturer | Analog Devices Inc./Maxim Integrated |
| Package / Case | 8-SOIC (0.154", 3.90mm Width) |
| Mounting Type | Surface Mount |
| Type | with Voltage Reference |
| Number of Elements | 1 |
| Output Type | CMOS, TTL |
| Voltage - Supply, Single/Dual (±) | 2.5V ~ 11V, ±1.25V ~ 5.5V |
| Voltage - Input Offset (Max) | 10mV @ 5V |
| Current - Output (Typ) | 50mA |
| Current - Quiescent (Max) | 5µA |
| CMRR, PSRR (Typ) | 80dB CMRR, 80dB PSRR |
| Propagation Delay (Max) | 12µs |
| Hysteresis | 50mV |
| Operating Temperature | 0°C ~ 70°C |
| Product Status | Obsolete |
| RoHS Status | RoHS non-compliant |
Substitute Part Grouping Explanation
Substitution of the MAX921CSA-T is determined by the following critical parameters:
- Package compatibility: 8-SOIC surface mount form factor
- Functional equivalence: Single-element comparator with integrated voltage reference
- Output type: CMOS and TTL output capability
- Supply voltage range: Minimum 2.5V single supply or ±1.25V dual supply operation
- Input offset voltage: Maximum 10mV @ 5V
- Propagation delay: Maximum 12µs
- Hysteresis: 50mV fixed
- Operating temperature range: 0°C ~ 70°C minimum
The MAX921CSA+T serves as a direct pin-compatible replacement with identical electrical specifications and active product status. The LTC1440 and LTC1540 series provide functional equivalence with minor parameter variations within acceptable engineering tolerances for comparator applications. These alternatives maintain the same package footprint, output type, and core voltage reference functionality while offering improved compliance status and extended temperature range options.
Parameter Comparison
| Parameter | MAX921CSA-T | MAX921CSA+T | LTC1440CS8#PBF | LTC1440CS8#TRPBF | LTC1440IS8#PBF | LTC1440IS8#TRPBF | LTC1540CS8#PBF | LTC1540CS8#TRPBF | LTC1540IS8#PBF | LTC1540IS8#TRPBF |
|---|---|---|---|---|---|---|---|---|---|---|
| Manufacturer | Analog Devices Inc./Maxim Integrated | Analog Devices Inc./Maxim Integrated | Analog Devices Inc. | Analog Devices Inc. | Analog Devices Inc. | Analog Devices Inc. | Analog Devices Inc. | Analog Devices Inc. | Analog Devices Inc. | Analog Devices Inc. |
| Package / Case | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) |
| Mounting Type | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount |
| Type | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference | with Voltage Reference |
| Number of Elements | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Output Type | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL | CMOS, TTL |
| Voltage - Supply, Single/Dual (±) | 2.5V ~ 11V, ±1.25V ~ 5.5V | 2.5V ~ 11V, ±1.25V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V | 2V ~ 11V, ±1V ~ 5.5V |
| Voltage - Input Offset (Max) | 10mV @ 5V | 10mV @ 5V | 10mV @ 5V | 10mV @ 5V | 10mV @ 5V | 10mV @ 5V | 12mV @ 5V | 12mV @ 5V | 12mV @ 5V | 12mV @ 5V |
| Current - Output (Typ) | 50mA | 50mA | 40mA | 40mA | 40mA | 40mA | — | — | — | — |
| Current - Quiescent (Max) | 5µA | 5µA | 4.4µA | 4.4µA | 4.4µA | 4.4µA | 680nA | 680nA | 710nA | 710nA |
| CMRR, PSRR (Typ) | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR | 80dB CMRR, 80dB PSRR |
| Propagation Delay (Max) | 12µs | 12µs | 15µs | 15µs | 15µs | 15µs | 60µs | 60µs | 60µs | 60µs |
| Hysteresis | 50mV | 50mV | 50mV | 50mV | 50mV | 50mV | 50mV | 50mV | 50mV | 50mV |
| Operating Temperature | 0°C ~ 70°C | 0°C ~ 70°C | 0°C ~ 70°C | 0°C ~ 70°C | -40°C ~ 85°C | -40°C ~ 85°C | 0°C ~ 70°C | 0°C ~ 70°C | -40°C ~ 85°C | -40°C ~ 85°C |
| Product Status | Obsolete | Active | Active | Active | Active | Active | Active | Active | Active | Active |
| RoHS Status | RoHS non-compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant |
| Packaging | — | Cut Tape (CT) & Digi-Reel® | Tube | Tape & Reel (TR) | Tube | Tape & Reel (TR) | Tube | Tape & Reel (TR) | Tube | Tape & Reel (TR) |
Engineering Selection Recommendations
The MAX921CSA+T is the primary direct replacement for the obsolete MAX921CSA-T. Both parts share identical electrical specifications and package footprint. The MAX921CSA+T offers the advantage of active product status and ROHS3 compliance, making it suitable for new designs and production environments with regulatory requirements.
The LTC1440 series (LTC1440CS8#PBF, LTC1440CS8#TRPBF, LTC1440IS8#PBF, LTC1440IS8#TRPBF) provides functional equivalence with slightly relaxed supply voltage minimum (2V versus 2.5V) and marginally increased propagation delay (15µs versus 12µs). These parts maintain active status and ROHS3 compliance. The industrial temperature range variants (LTC1440IS8#PBF and LTC1440IS8#TRPBF) extend operating temperature to -40°C ~ 85°C, suitable for applications requiring wider temperature performance.
The LTC1540 series (LTC1540CS8#PBF, LTC1540CS8#TRPBF, LTC1540IS8#PBF, LTC1540IS8#TRPBF) offers the lowest quiescent current consumption (680nA to 710nA) and extended propagation delay (60µs). These parts are appropriate for power-constrained applications where reduced standby current is prioritized. Industrial temperature variants (LTC1540IS8#PBF and LTC1540IS8#TRPBF) provide -40°C ~ 85°C operation.
All substitute parts maintain the same 8-SOIC package, single-element comparator architecture with voltage reference, CMOS/TTL output capability, 50mV hysteresis, and 80dB CMRR/PSRR performance. Selection between LTC1440 and LTC1540 families depends on propagation delay and quiescent current requirements specific to the application.
Frequently Asked Questions (FAQ)
Q: Can MAX921CSA+T be used as a direct replacement for MAX921CSA-T?
A: Yes. The MAX921CSA+T is pin-compatible and electrically identical to the MAX921CSA-T. Both parts operate with 2.5V ~ 11V single supply or ±1.25V ~ 5.5V dual supply, deliver 50mA typical output current, and exhibit 12µs maximum propagation delay. The primary difference is product status: MAX921CSA+T is active and ROHS3 compliant, while MAX921CSA-T is obsolete and RoHS non-compliant.
Q: What are the key differences between LTC1440 and LTC1540 series?
A: The LTC1440 series maintains 40mA typical output current and 4.4µA maximum quiescent current with 15µs propagation delay. The LTC1540 series reduces quiescent current to 680nA (CS8) or 710nA (IS8) but increases propagation delay to 60µs and does not specify typical output current. Both families share identical supply voltage range (2V ~ 11V single, ±1V ~ 5.5V dual), input offset voltage (10mV for LTC1440, 12mV for LTC1540), and 50mV hysteresis.
Q: Are packaging options interchangeable?
A: Packaging options (Tube, Tape & Reel, Cut Tape & Digi-Reel) do not affect electrical performance or pin compatibility. Selection depends on production volume and assembly process requirements. All packaging variants of a given part number maintain identical electrical specifications and 8-SOIC form factor.
Q: Which substitute is best for low-power applications?
A: The LTC1540 series is optimized for low-power operation with quiescent current of 680nA (CS8#PBF, CS8#TRPBF) or 710nA (IS8#PBF, IS8#TRPBF). This represents a 99% reduction in quiescent current compared to the MAX921CSA-T (5µA). The trade-off is increased propagation delay (60µs versus 12µs), which is acceptable for applications where speed is not critical.
Q: What is the difference between commercial and industrial temperature variants?
A: Commercial temperature variants (CS8 suffix) operate from 0°C ~ 70°C. Industrial temperature variants (IS8 suffix) operate from -40°C ~ 85°C. Industrial variants are required for applications exposed to extended temperature ranges or harsh environmental conditions. All other electrical specifications remain identical between commercial and industrial versions within each family.
Q: Is the 2mV difference in input offset voltage between LTC1440 and LTC1540 significant?
A: The LTC1440 series specifies 10mV maximum input offset voltage, while LTC1540 specifies 12mV maximum. This 2mV difference is within typical comparator tolerance and does not affect pin compatibility or functional equivalence. Selection should be based on application-specific offset voltage requirements rather than this marginal difference.
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