My Inquiry
My Account
Analog Devices Inc. LTC1261LIMS8#PBF
- Part No.:
- LTC1261LIMS8#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LTC1261LIMS8#PBF.pdf
- Description:
- IC REG CHARG PUMP ADJ 20MA 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:912
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1261LIMS8#PBF from Analog Devices (formerly Linear Technology) is a switched-capacitor regulated negative voltage inverter IC designed to generate a stable –4V output from a single 4.5V–5.25V positive supply. It delivers up to 20mA output current with ±4.5% regulation accuracy, features an open-drain REG flag for power-valid indication, and operates in industrial temperature range (–40°C to +85°C) in an 8-pin MSOP package.
For engineers reviewing the LTC1261LIMS8#PBF datasheet, LTC1261LIMS8#PBF pinout, LTC1261LIMS8#PBF application, or LTC1261LIMS8#PBF equivalent, key selection criteria include guaranteed output regulation over full temperature range, shutdown quiescent current of 5µA, internal 650kHz oscillator, ADJ/COMP pin for ripple compensation, and compatibility with ceramic flying/output capacitors.
Technical Context
The LTC1261LIMS8#PBF implements a fixed-output inverting charge pump architecture using internal MOSFET switches gated by a 650kHz oscillator. Regulation is achieved via feedback comparison of a divided output voltage against a 1.23V internal reference, with cycle-by-cycle charge transfer control to maintain output within ±4.5% tolerance.
Its REG pin functions as an open-drain indicator that pulls low when output magnitude is within 5% of the setpoint (e.g., VOUT ≥ –3.8V for –4V output), sinking up to 5mA at 5V VCC. Shutdown is activated by pulling SHDN high, reducing supply current to 5µA while collapsing output to 0V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed –4V, guaranteed across –40°C to +85°C and 0–20mA load |
| Input Supply Range | 4.35V to 5.25V - minimum VCC ensures ±4.5% regulation at full load |
| Output Regulation Accuracy | ±4.5% - defines worst-case deviation from nominal –4V under all operating conditions |
| Supply Current (Active) | 650µA typical - determines system-level power budget in active mode |
| Shutdown Current | 5µA typical - enables ultra-low-power standby in battery systems |
| Oscillator Frequency | 650kHz - sets charge-transfer timing and dictates minimum output capacitor size for ripple control |
| REG Output Sink Capability | 5mA at 5V VCC - supports direct interface to logic-level pull-up resistors or microcontroller inputs |
Pinout & Package
Package: 8-lead plastic MSOP (MS8), 3.0mm × 3.0mm body, 0.65mm pitch, exposed pad not electrically connected.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC (Pin 1) | Positive power input | Must be bypassed with ≥1µF ceramic capacitor near pin; supplies energy for charge pumping |
| C1+ (Pin 2) | Flying capacitor positive terminal | Connects to top plate of 0.1µF flying capacitor; carries switching current during charge transfer |
| C1– (Pin 3) | Flying capacitor negative terminal | Connects to bottom plate of 0.1µF flying capacitor; referenced to ground during charging phase |
| GND (Pin 4) | Analog and power ground | Low-impedance return path for flying capacitor and output current; critical for regulation stability |
| ADJ/COMP (Pin 5) | Feedback/compensation node | Internally tied to resistor divider for –4V output; optional 100pF to ground reduces output ripple |
| OUT (Pin 6) | Negative regulated output | Requires ≥3.3µF output capacitor; ESR impacts regulation loop stability and ripple |
| REG (Pin 7) | Open-drain regulation status flag | Pulls low when |VOUT| ≥ 95% of setpoint; requires external pull-up to VCC or logic rail |
| SHDN (Pin 8) | Enable/disable control | Logic-high disables charge pump and drops ICC to 5µA; internal 5µA pull-down holds active if floating |
Key Features
| Feature | Design Value |
|---|---|
| Fixed –4V output with ±4.5% regulation | Eliminates external resistor network; guarantees accuracy over industrial temperature range |
| 650kHz internal oscillator | Enables use of small 0.1µF flying capacitor and minimizes EMI compared to lower-frequency pumps |
| REG open-drain status output | Provides hardware-level power-good signal without additional monitoring circuitry |
| 5µA shutdown quiescent current | Extends battery life in portable GaAs FET bias and handheld instrumentation applications |
| MSOP-8 package with thermal performance | θJA = 200°C/W enables operation at full 20mA load without heatsink in compact layouts |
Applications
| GaAs FET Bias Generator | Negative Supply Generator |
|---|---|
Use Scenario: Generating precise –4V gate bias for GaAs power amplifier stages in RF transmitters. IC Role / Device Role / Timing Role: Regulated negative voltage source providing stable gate control voltage independent of VCC variation. Use Value: Enables consistent amplifier linearity and gain by maintaining exact –4V bias despite input supply droop or temperature drift. | Use Scenario: Creating isolated negative rail for op-amp dual-supply operation in single-supply systems. IC Role / Device Role / Timing Role: Compact, capacitor-based inverter delivering clean –4V output without inductors or transformers. Use Value: Reduces BOM count and board area versus discrete charge-pump or inductor-based solutions while meeting ±4.5% regulation spec. |
| Battery-Powered Instrumentation | Single-Supply Signal Conditioning |
Use Scenario: Powering precision analog front-ends in portable test equipment requiring bipolar supplies. IC Role / Device Role / Timing Role: Low-quiescent-current (5µA shutdown) negative rail generator enabling long battery runtime. Use Value: Extends operational time between battery replacements while maintaining ADC reference stability via regulated –4V. | Use Scenario: Providing negative supply to rail-to-rail op-amps in sensor signal conditioning circuits. IC Role / Device Role / Timing Role: Fixed-output inverter ensuring consistent offset nulling and common-mode rejection. Use Value: Eliminates output swing limitation in single-supply amplifiers, enabling true bipolar signal handling down to 0V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar regulated negative voltage inverter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1261LCS8-4#PBF | Same electrical specs but SO-8 package (θJA = 135°C/W) and commercial temp range (0°C to 70°C) | Suitable for cost-sensitive, non-industrial environments where thermal margin is higher | Select when PCB layout allows larger SO-8 footprint and ambient temperature stays below 70°C |
| MAX680ESA+ | Fixed –5V output, 100kHz oscillator, ±1.5% regulation, SO-8 only, no REG pin | Lacks power-valid flag and tighter regulation; higher output ripple due to lower frequency | Choose only if –5V output suffices and system does not require regulation status monitoring |
Compared with LTC1261LCS8-4#PBF, the LTC1261LIMS8#PBF offers extended temperature support and better thermal resistance for high-density layouts; versus MAX680ESA+, it provides superior regulation accuracy, integrated power-good signaling, and higher switching frequency for smaller external components.
Availability
LTC1261LIMS8#PBF is available at Aetrix Electronics and suitable for GaAs FET bias generators, portable instrumentation power supplies, and single-supply signal conditioning circuits requiring stable component supply across industrial temperature ranges.
Supply support for LTC1261LIMS8#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices acquired Linear Technology in 2017 and maintains its legacy precision analog and power management portfolio with full datasheet, reliability, and support continuity.
The LTC1261LIMS8#PBF belongs to Linear's switched-capacitor DC/DC converter family, engineered for low-noise, inductorless negative voltage generation in space-constrained and battery-sensitive applications.
FAQ
What is the minimum input voltage required for LTC1261LIMS8#PBF to maintain –4V output regulation?
The LTC1261LIMS8#PBF requires a minimum supply voltage of 4.35V to guarantee ±4.5% output regulation across its full –40°C to +85°C operating range and 0–20mA load. Below this, regulation accuracy degrades; operation down to 4.0V is possible but not specified for regulation performance. This requirement is explicitly defined in the Electrical Characteristics table for the -4 variant.
Does LTC1261LIMS8#PBF require external resistors to set its –4V output?
No, the LTC1261LIMS8#PBF does not require external resistors. Its –4V output is internally trimmed and fixed via on-die resistor networks connected to the ADJ/COMP pin. External resistors are only needed for adjustable versions like the base LTC1261L; the "-4" suffix denotes factory-configured fixed output.
Can the REG pin of LTC1261LIMS8#PBF be pulled up to a voltage higher than VCC?
Yes, the REG pin of LTC1261LIMS8#PBF is rated to 6V maximum above ground and may be pulled up to any voltage ≤6V, including rails higher than VCC (e.g., 5V REG pull-up with 3.3V VCC). This is confirmed in the Absolute Maximum Ratings table and Applications Information section, which states the pin "can be pulled up to 6V above ground without damage."
What capacitor values are mandatory for stable operation of LTC1261LIMS8#PBF?
The LTC1261LIMS8#PBF requires three mandatory capacitors: a 0.1µF ceramic flying capacitor between C1+ and C1–, a ≥1µF ceramic input bypass capacitor from VCC to GND, and a ≥3.3µF ceramic output capacitor from OUT to GND. An optional 100pF capacitor from ADJ/COMP to GND is recommended to minimize output ripple, especially under dynamic load.
Is LTC1261LIMS8#PBF pin-compatible with LTC1261LCS8-4#PBF?
Yes, the LTC1261LIMS8#PBF is pin-compatible with LTC1261LCS8-4#PBF. Both share identical 8-pin MSOP and SO-8 footprints respectively, with identical pin numbering, functions, and electrical behavior. The only differences are package type (MSOP vs SO-8), thermal characteristics (θJA = 200°C/W vs 135°C/W), and operating temperature range (–40°C to +85°C vs 0°C to +70°C).
LTC1261LIMS8#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Negative
- Topology:
- Charge Pump
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.25V
- Voltage - Output (Min/Fixed):
- -1.23V
- Voltage - Output (Max):
- -5V
- Current - Output:
- 20mA
- Frequency - Switching:
- 650kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
LTC1261LIMS8#PBF FAQ
1.How can I place an order for LTC1261LIMS8#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1261LIMS8#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LTC1261LIMS8#PBF reliable?
The price and inventory of LTC1261LIMS8#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1261LIMS8#PBF is usually 5 days.
3.What payment methods are accepted for LTC1261LIMS8#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1261LIMS8#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1261LIMS8#PBF?
LTC1261LIMS8#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1261LIMS8#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LTC1261LIMS8#PBF?
For technical support, including LTC1261LIMS8#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1261LIMS8#PBF requirements.
6.How does Aetrix verify that LTC1261LIMS8#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1261LIMS8#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LTC1261LIMS8#PBF meets industry standards.
7.What is the process for return or replacement of LTC1261LIMS8#PBF?
All LTC1261LIMS8#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1261LIMS8#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LTC1261LIMS8#PBF part is unused and in its original packaging.
Return procedure for LTC1261LIMS8#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1261LIMS8#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
