MMBTA55 PNP Bipolar Junction Transistor Equivalent & Substitute Parts

Part Overview

The MMBTA55 is a PNP bipolar junction transistor manufactured by onsemi, rated for 60 V collector-emitter breakdown voltage and 500 mA maximum collector current in a surface mount SOT-23-3 package. The device is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and production continuity. Substitute parts must maintain electrical compatibility within the specified parameter ranges while meeting current manufacturing and compliance standards.

Key Parameters

Parameter	Value	Unit
Transistor Type	PNP	—
Collector Current (Ic) Maximum	500	mA
Collector-Emitter Breakdown Voltage (Max)	60	V
Vce Saturation (Max)	250	mV @ 10mA, 100mA
Collector Cutoff Current (Max)	100	nA
DC Current Gain (hFE) Minimum	100	@ 100mA, 1V
Power Dissipation (Max)	350	mW
Transition Frequency	50	MHz
Operating Temperature Range	-55 to 150	°C
Package Type	SOT-23-3 (TO-236-3, SC-59)	—
Mounting Type	Surface Mount	—

Substitute Part Grouping Explanation

Substitute parts for the MMBTA55 are classified into two categories based on electrical parameter compatibility:

Direct Substitutes maintain all critical electrical parameters within the MMBTA55 specification envelope: 60 V collector-emitter breakdown voltage, 500 mA maximum collector current, 100 mA minimum DC current gain at 100 mA collector current and 1 V collector-emitter voltage, and SOT-23-3 package compatibility. These parts are pin-compatible and functionally interchangeable without circuit modification.

Similar Substitutes operate within reduced voltage ratings (45 V collector-emitter breakdown) or modified electrical characteristics while maintaining the same package footprint and basic PNP transistor functionality. These parts are suitable for applications where the 60 V rating is not required and where the alternative electrical specifications meet circuit requirements.

The following parameters determine substitution eligibility:

Transistor polarity (PNP)
Collector-emitter breakdown voltage (minimum 45 V for similar substitutes; 60 V for direct substitutes)
Maximum collector current (500 mA minimum)
DC current gain (100 minimum at specified test conditions)
Surface mount package compatibility (SOT-23-3 or equivalent footprint)
Operating temperature range (-55°C to 150°C minimum)

Parameter Comparison

Part Number	Manufacturer	Ic (Max) mA	Vce(br) V	Vce Sat mV	hFE (Min)	Power mW	Freq MHz	Package	Status
MMBTA55	onsemi	500	60	250 @ 10mA, 100mA	100 @ 100mA, 1V	350	50	SOT-23-3	Obsolete
MMBTA55LT1G	onsemi	500	60	250 @ 10mA, 100mA	100 @ 100mA, 1V	225	50	SOT-23-3	Active
MMBTA55-7-F	Diodes Incorporated	500	60	250 @ 10mA, 100mA	100 @ 100mA, 1V	300	50	SOT-23-3	Active
BC807-16 RFG	Taiwan Semiconductor Corporation	500	45	700 @ 50mA, 500mA	100 @ 100mA, 1V	300	100	SOT-23	Active
BC807-25,215	Nexperia USA Inc.	500	45	700 @ 50mA, 500mA	160 @ 100mA, 1V	250	80	TO-236AB	Active
BC807K-40VL	Nexperia USA Inc.	500	45	700 @ 50mA, 500mA	250 @ 100mA, 1V	250	80	TO-236AB	Active
BCX17,215	Nexperia USA Inc.	500	45	620 @ 50mA, 500mA	100 @ 100mA, 1V	250	80	TO-236AB	Active
BCX17T116	Rohm Semiconductor	500	45	620 @ 50mA, 500mA	100 @ 100mA, 1V	425	200	SST3	Active
CMPT2907A BK PBFREE	Central Semiconductor Corp	600	60	1600 @ 50mA, 500mA	100 @ 150mA, 10V	350	200	SOT-23	Active
CMPT2907A TR PBFREE	Central Semiconductor Corp	600	60	1600 @ 50mA, 500mA	100 @ 150mA, 10V	350	200	SOT-23	Active
CMPT2907AE TR PBFREE	Central Semiconductor Corp	600	60	700 @ 50mA, 500mA	100 @ 150mA, 10V	350	200	SOT-23	Active

Engineering Selection Recommendations

Direct Substitutes (Recommended for Pin-Compatible Replacement)

MMBTA55LT1G (onsemi) and MMBTA55-7-F (Diodes Incorporated) are direct electrical equivalents of the MMBTA55. Both maintain the 60 V collector-emitter breakdown voltage, 500 mA maximum collector current, and identical saturation voltage specifications. MMBTA55LT1G is an active onsemi product with RoHS3 compliance and unlimited moisture sensitivity level. MMBTA55-7-F is manufactured by Diodes Incorporated with AEC-Q101 automotive qualification, RoHS3 compliance, and active product status. Selection between these two depends on supply chain availability and automotive qualification requirements.

Similar Substitutes (For Reduced Voltage Applications)

BC807 series parts (BC807-16 RFG, BC807-25,215, BC807K-40VL) and BCX17 series parts (BCX17,215, BCX17T116) operate at 45 V collector-emitter breakdown voltage. These are suitable for applications where the 60 V rating is not required. BC807-25,215 and BC807K-40VL include AEC-Q101 automotive qualification. BCX17T116 offers the highest transition frequency (200 MHz) among similar substitutes.

Central Semiconductor CMPT2907A Series

CMPT2907A BK PBFREE, CMPT2907A TR PBFREE, and CMPT2907AE TR PBFREE maintain the 60 V collector-emitter breakdown voltage and are rated for 600 mA maximum collector current. These parts feature higher transition frequency (200 MHz) and are available in active product status with RoHS3 compliance. The CMPT2907AE variant offers improved saturation voltage characteristics (700 mV) compared to CMPT2907A variants (1600 mV).

All recommended substitutes are RoHS3 compliant, have unlimited moisture sensitivity level (MSL 1), and maintain surface mount packaging compatibility with the original MMBTA55.

Frequently Asked Questions (FAQ)

Q: Can MMBTA55LT1G be used as a direct replacement for MMBTA55?

A: Yes. MMBTA55LT1G maintains identical electrical specifications for collector current (500 mA), collector-emitter breakdown voltage (60 V), saturation voltage (250 mV @ 10mA, 100mA), and DC current gain (100 @ 100mA, 1V). Both use SOT-23-3 packaging. The primary difference is product status: MMBTA55LT1G is active while MMBTA55 is obsolete.

Q: What is the difference between direct substitutes and similar substitutes?

A: Direct substitutes maintain all electrical parameters of the MMBTA55, including the 60 V collector-emitter breakdown voltage. Similar substitutes operate at reduced voltage ratings (45 V) but maintain the same collector current (500 mA) and basic PNP transistor functionality. Similar substitutes are suitable only for applications where the lower voltage rating is acceptable.

Q: Can BC807 series parts replace MMBTA55 in all applications?

A: BC807 series parts are suitable only for applications where the 60 V collector-emitter breakdown voltage is not required. These parts are rated for 45 V maximum. If the circuit design requires 60 V breakdown voltage margin, BC807 series parts are not appropriate substitutes.

Q: What is the significance of the CMPT2907A higher collector current rating (600 mA vs. 500 mA)?

A: The CMPT2907A series is rated for 600 mA maximum collector current, exceeding the MMBTA55 specification of 500 mA. This provides additional current capacity but does not affect substitution compatibility. The part can be used in applications designed for 500 mA operation without modification.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed in this reference are RoHS3 compliant. The original MMBTA55 has REACH Unaffected status; all active substitutes maintain REACH Unaffected status and RoHS3 compliance.

Q: What packaging considerations apply to BCX17T116?

A: BCX17T116 uses SST3 packaging, which is mechanically compatible with SOT-23-3 footprints but may have different thermal characteristics. Verify PCB layout compatibility with the specific SST3 package dimensions before implementation.

Q: Which substitute offers the best high-frequency performance?

A: BCX17T116 and CMPT2907A series parts offer the highest transition frequency at 200 MHz, compared to the original MMBTA55 at 50 MHz. BC807 series parts operate at 80–100 MHz. Selection depends on circuit frequency requirements.

Q: Do automotive-qualified substitutes exist?

A: Yes. MMBTA55-7-F (Diodes Incorporated, AEC-Q101), BC807-25,215 (Nexperia, AEC-Q101), BC807K-40VL (Nexperia, AEC-Q100), and BCX17,215 (Nexperia, AEC-Q101) include automotive qualification. These are suitable for automotive applications requiring component traceability and qualification documentation.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message