LT1121ACS8#PBF Analog Devices Integrated Circuit (Small Outline Packages) In Stock
Analog Devices LT1121ACS8#PBF is an adjustable micropower low-dropout regulator with shutdown in an 8-pin SOIC package. Features 0.42V typical dropout voltage and up to 19.3V input-output differential for wide supply range applications. RoHS-compliant lead-free version available worldwide with 9+ years estimated product lifetime.
- Manufacturer
- Analog Devices
- Package
- Small Outline Packages
- Pin Count
- 8
- Lifecycle
- ACTIVE
- Datasheet
- LT1121ACS8#PBF Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $3.4000(MOQ 19)
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Adjustable output voltage via external resistor divider with only 0.42V typical dropout for efficient low-headroom regulation
- Micropower quiescent current in shutdown mode for ultra-low standby power in battery-operated portable equipment
- Wide 19.3V maximum input-output differential supports operation from 5V to 24V supply rails in industrial designs
- Shutdown pin enables system power sequencing and load switching without external discrete transistors in 8-pin SOIC footprint
Applications
The LT1121ACS8#PBF is used in battery-powered portable instruments and handheld medical devices that require a programmable output voltage with micropower shutdown to conserve energy during sleep modes. Its wide 19.3V input-output differential makes it suitable for industrial sensor nodes and field transmitters powered from 12V to 24V supply rails that need a precise lower-voltage reference or logic supply. The 8-pin SOIC package and adjustable topology also suit laboratory power supply modules and mixed-signal PCBs where output voltage must be tuned by the end user via external resistors.
Specifications
| Pbfree Code | No |
| Manufacturer Package Code | 05-08-1610 (S8) |
| YTEOL | 9 |
| Adjustability | ADJUSTABLE |
| Dropout Voltage1-Max | 0.7V |
| Dropout Voltage1-Nom | 0.42V |
| Input-Output Voltage Differential-Max | 19.3V |
| Input-Output Voltage Differential-Min | 0.55V |
| JESD-30 Code | R-PDSO-G8 |
| JESD-609 Code | e3 |
| Line Regulation-Max (%/V) | 0.017 |
| Load Regulation-Max(%) | 1.07% |
| Number of Functions | 1 |
| Number of Outputs | 1 |
| Operating Temperature TJ-Max | 125°C |
| Output Current1-Max | 0.15A |
| Output Voltage1-Max | 30V |
| Output Voltage1-Min | 3.75V |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP8,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Packing Method | TUBE |
| Peak Reflow Temperature (Cel) | 260 |
| Qualification Status | Not Qualified |
| Regulator Type | ADJUSTABLE POSITIVE SINGLE OUTPUT LDO REGULATOR |
| Surface Mount | YES |
| Technology | BIPOLAR |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Malaysia |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What dropout voltage does the LT1121ACS8#PBF exhibit at full load, and which battery chemistries benefit from this low dropout?
The LT1121ACS8#PBF has a typical dropout voltage of 0.42V and a maximum of 0.7V at rated output current. This low dropout allows a 3.3V regulated output to be maintained from a nearly discharged single-cell Li-ion battery at 4.0V, extending usable capacity by 15-20% compared to a standard LDO with 1.5V dropout, making it ideal for wearables and handheld meters on single-cell Li-ion or NiMH 3-cell packs.
How should engineers set the output voltage of the LT1121ACS8#PBF using external resistors, and what is the adjustment range?
The LT1121ACS8#PBF output is set by a resistor divider from the output to the adjust pin. The internal reference is typically 1.24V, so two resistors of 10kΩ and a variable resistor between 1kΩ and 100kΩ can program outputs from approximately 1.5V to over 20V, limited by the 19.3V maximum input-output differential. A 1% tolerance resistor pair provides output accuracy better than ±2% across temperature.
In what power-sequencing designs does the LT1121ACS8#PBF shutdown pin provide an advantage over a separate load switch?
The LT1121ACS8#PBF shutdown pin draws less than 1µA when asserted, cutting output current to near zero without an external P-channel MOSFET or load switch IC. This eliminates 1-2 discrete components and reduces PCB area by approximately 15mm², which is valuable in multi-rail power trees for FPGAs and DSPs requiring precise 1ms power-up sequencing between 1.8V, 2.5V, and 3.3V rails controlled by a single microcontroller GPIO.
When is the LT1121ACS8#PBF a lower-cost alternative to a switching regulator for an industrial 24V-to-3.3V supply rail?
For loads below 100mA on a 24V bus converting to 3.3V, the LT1121ACS8#PBF's total BOM (2 resistors, 2 capacitors, 1 IC) costs roughly 60-70% less than a comparable switching regulator solution requiring an inductor, diode, and controller IC. The linear dropout solution also eliminates switching noise on the 3.3V rail, which is critical for 12-bit or 16-bit ADC reference supplies where switching ripple above 1mV pk-pk degrades effective number of bits.
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About Analog Devices
Analog Devices (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing integrated circuits used in virtually all types of electronic equipment.
More from Analog Devices
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 19+ | $4.5100 | $85.69 |
| 100+ | $4.1855 | $418.55 |
| 500+ | $3.7000 | $1850.00 |
| 1000+ | $3.4000 | $3400.00 |
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