FT511AB Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The FT511AB is a linear voltage regulator IC manufactured by Fremont Micro Devices Ltd, designed for positive fixed 1.2V output at 150mA in a SOT-89-3LA surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The FT511AB operates across -40°C to 85°C with a maximum input voltage of 5.5V and features over-current protection.

Key Parameters

Parameter	FT511AB Specification
Manufacturer	Fremont Micro Devices Ltd
Output Voltage (Fixed)	1.2V
Output Current	150mA
Input Voltage (Max)	5.5V
Dropout Voltage (Max)	0.7V @ 100mA
Quiescent Current	1.6 µA
Operating Temperature	-40°C ~ 85°C
Package / Case	TO-243AA (SOT-89-3LA)
Mounting Type	Surface Mount
Protection Features	Over Current
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution for the FT511AB is determined by the following critical parameters:

Fixed output voltage of 1.2V
Positive output configuration
Surface mount package compatibility (TO-243AA / SOT-89-3)
Maximum input voltage of 5.5V
Operating temperature range of -40°C to 85°C or wider
Output current capability equal to or greater than 150mA

The substitute parts listed below meet these core electrical and mechanical requirements. Differences in quiescent current, dropout voltage, and maximum output current are secondary considerations that depend on specific application requirements.

Parameter Comparison

Parameter	FT511AB	MCP1700T-1202E/MB	AP7217D-12YG-13	RT9166-12GX
Manufacturer	Fremont Micro Devices Ltd	Microchip Technology	Diodes Incorporated	Richtek USA Inc.
Output Voltage (Fixed)	1.2V	1.2V	1.2V	1.2V
Output Current	150mA	200mA	600mA	300mA
Input Voltage (Max)	5.5V	6V	5.5V	5.5V
Dropout Voltage (Max)	0.7V @ 100mA	0.35V @ 200mA	1.3V @ 600mA	0.23V @ 300mA (Typ)
Quiescent Current	1.6 µA	4 µA	60 µA	300 µA
Operating Temperature	-40°C ~ 85°C	-40°C ~ 125°C	-40°C ~ 85°C	-40°C ~ 85°C
Package / Case	TO-243AA	TO-243AA	TO-243AA	TO-243AA
Protection Features	Over Current	Over Current, Over Temperature, Short Circuit	Over Current, Over Temperature	Over Current, Over Temperature
Product Status	Obsolete	Active	Last Time Buy	Active
RoHS Status	Not specified	ROHS3 Compliant	Not specified	ROHS3 Compliant

Engineering Selection Recommendations

MCP1700T-1202E/MB is the primary substitute for the FT511AB. This part is actively manufactured by Microchip Technology, offers superior dropout voltage performance (0.35V @ 200mA), and provides extended operating temperature range to 125°C. The MCP1700T-1202E/MB includes comprehensive protection features (over-current, over-temperature, and short-circuit) and maintains ROHS3 compliance. Output current of 200mA exceeds the FT511AB requirement of 150mA.

RT9166-12GX is an alternative substitute offering the lowest dropout voltage (0.23V @ 300mA typical) and higher output current capability (300mA). This part is actively manufactured by Richtek USA Inc. and provides ROHS3 compliance. The higher quiescent current (300 µA) may be a consideration in ultra-low-power applications.

AP7217D-12YG-13 is a substitute with the highest output current capability (600mA) but carries a higher dropout voltage (1.3V @ 600mA) and elevated quiescent current (60 µA). This part is in Last Time Buy status and carries MSL-3 moisture sensitivity. Selection of this part should account for its higher power dissipation characteristics.

Frequently Asked Questions (FAQ)

Q: Can MCP1700T-1202E/MB directly replace FT511AB without circuit modifications?

A: Yes. Both parts share identical output voltage (1.2V), package type (TO-243AA), and mounting configuration. The MCP1700T-1202E/MB provides superior electrical performance with lower dropout voltage and higher output current capability. No circuit modifications are required.

Q: What is the primary difference between the three substitute parts?

A: Output current capability and dropout voltage characteristics differ. MCP1700T-1202E/MB provides 200mA at 0.35V dropout. RT9166-12GX provides 300mA at 0.23V dropout (typical). AP7217D-12YG-13 provides 600mA at 1.3V dropout. Selection depends on application current requirements and acceptable power dissipation.

Q: Are all substitute parts ROHS3 compliant?

A: MCP1700T-1202E/MB and RT9166-12GX are ROHS3 compliant. AP7217D-12YG-13 compliance status is not specified in available documentation.

Q: Does operating temperature range affect substitution suitability?

A: MCP1700T-1202E/MB extends the upper operating temperature to 125°C compared to the FT511AB specification of 85°C. RT9166-12GX and AP7217D-12YG-13 maintain the 85°C upper limit. For applications requiring extended temperature operation, MCP1700T-1202E/MB is the appropriate selection.

Q: What is the significance of quiescent current differences?

A: Quiescent current affects standby power consumption. FT511AB specifies 1.6 µA. MCP1700T-1202E/MB specifies 4 µA. RT9166-12GX specifies 300 µA. AP7217D-12YG-13 specifies 60 µA. For battery-powered or ultra-low-power applications, MCP1700T-1202E/MB remains the lowest-consumption option among active substitutes.

Q: Is packaging compatibility guaranteed across all substitutes?

A: All substitute parts use TO-243AA package (SOT-89-3 or SOT-89-3LA variants). Physical footprint and pin configuration are compatible. Verify PCB layout accommodates the specific supplier device package designation if transitioning between manufacturers.

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