My Inquiry
My Account
Analog Devices Inc. LTC1550LCMS8-2.5#PBF
- Part No.:
- LTC1550LCMS8-2.5#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LTC1550LCMS8-2.5#PBF.pdf
- Description:
- IC REG CHARGE PUMP -2.5V 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,695
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1550LCMS8-2.5#PBF from Analog Devices (formerly Linear Technology) is a low-noise, switched-capacitor regulated negative voltage inverter with integrated linear post-regulator, delivering a fixed –2.5V output at up to 20mA load current, <1mVP-P ripple, and 900kHz charge pump frequency. It operates from a single 3.05V–5.25V supply and features active-low TTL-compatible shutdown (SHDN), making it suitable for GaAs FET bias generation in portable RF transmitters.
For engineers reviewing the LTC1550LCMS8-2.5#PBF datasheet, LTC1550LCMS8-2.5#PBF pinout, LTC1550LCMS8-2.5#PBF application, or LTC1550LCMS8-2.5#PBF equivalent, key selection criteria include guaranteed ±2.5% output regulation over line/load/temperature, minimal external component count (four capacitors), MSOP-8 package compatibility, and shutdown quiescent current <1µA.
Technical Context
The LTC1550LCMS8-2.5#PBF integrates a 900kHz inverting charge pump stage followed by a negative linear regulator using an N-channel MOSFET pass device and internal 1.225V reference. Its feedback loop is optimized for fast transient response to suppress switching artifacts from CPOUT, enabling stable regulation under dynamic loads.
It requires no external resistors for fixed –2.5V operation, uses only 0.1µF flying and storage capacitors, and relies on star-ground layout of VCC, CPOUT, and VOUT bypass capacitors to maintain sub-millivolt ripple. The REG pin provides open-drain power-good indication referenced to VOUT.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed –2.5V, regulated to ±2.5% over line, load (0–20mA), and temperature (0°C to 70°C) |
| Output Ripple | <1mVP-P typical with 10µF + 0.1µF output capacitor; enables clean bias for sensitive RF FETs |
| Supply Range | 3.05V to 5.25V minimum input required for –2.5V output at full 20mA load |
| Charge Pump Freq | 900kHz internal oscillator - avoids IF bands (400–600kHz), reduces capacitor size, minimizes EMI |
| Shutdown Current | 0.2µA typical - enables ultra-low-power sleep mode in battery-operated systems |
| Quiescent Current | 3.65mA typical at 5V supply - balances efficiency and startup speed for portable applications |
| Turn-On Time | 1–5ms depending on load and output voltage - ensures predictable power sequencing in RF subsystems |
Pinout & Package
Package: 8-lead MSOP (MS8), 3.0mm × 3.0mm × 0.85mm body, exposed pad not electrically connected, RoHS-compliant #PBF finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (REG) | Open-drain power-good output | Pulls low when |VOUT| is within 5% of target; requires external pull-up to ≥2.5V; sinks 4mA max |
| 2 (CPOUT) | Negative charge pump output | Drives 0.1µF storage capacitor to ground; critical AC return path must tie directly to GND and VCC bypass |
| 3 (GND) | Analog/power ground reference | Single-pin ground for 8-lead MSOP; must connect to low-impedance plane to minimize regulation error |
| 4 (C1–) | Negative flying capacitor terminal | Completes charge transfer path with C1+; connects 0.1µF ceramic capacitor to C1+ |
| 5 (SHDN) | Active-low shutdown control | TTL-compatible input; pulls low to disable charge pump and reduce IQ to 0.2µA; no internal pull-up |
| 6 (VCC) | Positive supply input | Accepts 3.05–5.25V; requires ≥2.2µF low-ESR ceramic bypass to GND placed adjacent to pin |
| 7 (C1+) | Positive flying capacitor terminal | Charges C1 during first clock phase; connects 0.1µF ceramic capacitor to C1– |
| 8 (VOUT) | Regulated negative output | Delivers –2.5V; requires ≥10µF output capacitor (moderate ESR) + 0.1µF ceramic in parallel for stability and ripple |
Key Features
| Feature | Design Value |
|---|---|
| Integrated linear post-regulator | Eliminates need for external LDO; achieves <1mVP-P ripple without LC filtering |
| 900kHz charge pump frequency | Enables use of standard 0.1µF ceramic flying/storage capacitors; avoids interference with cellular IF bands |
| Fixed –2.5V output version | No external feedback resistors required; simplifies BOM and layout for GaAs bias applications |
| Star-ground optimized architecture | Minimizes ground loop noise; requires dedicated PCB trace routing for CPOUT/VOUT/VCC bypass returns |
| Power-good (REG) indicator | Provides system-level monitoring of output regulation status without additional ICs or firmware polling |
Applications
| GaAs FET Transmitter Bias | Negative Supply for Op-Amp Rails |
|---|---|
Use Scenario: Generating stable –2.5V gate bias for GaAs FETs in 3G/4G handset power amplifiers. IC Role / Device Role / Timing Role: Primary regulated negative voltage source; replaces discrete charge pump + LDO solutions. Use Value: Enables 20mA bias current with <1mVP-P ripple, preserving amplifier linearity and adjacent-channel power ratio (ACPR). | Use Scenario: Providing dual-rail supply for rail-to-rail op-amps in portable instrumentation front-ends. IC Role / Device Role / Timing Role: Negative rail generator; complements existing +2.5V LDO to create symmetric ±2.5V supplies. Use Value: Delivers low-noise –2.5V with fast transient response, minimizing offset drift and settling time in precision analog signal chains. |
| Battery-Powered RF Sensors | Low-Power IoT Node Biasing |
Use Scenario: Powering narrowband LoRa/GNSS receiver front-ends requiring clean –2.5V local oscillator bias. IC Role / Device Role / Timing Role: Low-quiescent, shutdown-capable negative supply; synchronized with MCU wake/sleep cycles. Use Value: Achieves 0.2µA shutdown current and 1–5ms turn-on, extending coin-cell battery life while maintaining RF sensitivity. | Use Scenario: Biasing MEMS oscillators or low-dropout regulators in energy-harvesting sensor nodes. IC Role / Device Role / Timing Role: Compact, capacitor-only negative voltage source; fits in space-constrained 2-layer PCB designs. Use Value: Requires only four 0402/0603 capacitors - eliminates inductors and reduces bill-of-materials cost vs. inductive DC/DC solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar negative voltage inverter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1550LCS8-2.5#PBF | Same electrical specs; SO-8 package (4.9mm × 3.9mm) vs. MSOP-8 (3.0mm × 3.0mm); higher θJA (200°C/W) | Less board-area efficient; better suited for through-hole prototyping or legacy SO footprints | Select for compatibility with existing SO-8 layouts or thermal environments where MSOP heat dissipation is constrained |
| LTC1261LCS8-2.5#PBF | Lower output current (15mA max); higher ripple (2mVP-P); no REG pin; 100kHz charge pump | Not suitable for high-speed RF bias; lacks power-good signaling for system monitoring | Choose only if cost is primary constraint and 20mA/1mV ripple requirements are relaxed |
Compared with LTC1550LCS8-2.5#PBF and LTC1261LCS8-2.5#PBF, the LTC1550LCMS8-2.5#PBF offers superior board-area efficiency, lower thermal resistance, and integrated power-good signaling - critical for miniaturized, thermally sensitive RF modules requiring deterministic power sequencing.
Availability
LTC1550LCMS8-2.5#PBF is available at Aetrix Electronics and suitable for GaAs FET biasing, portable RF sensor powering, and low-noise dual-rail op-amp supply applications requiring stable component supply, consistent parametric performance, and long-term industrial availability.
Supply support for LTC1550LCMS8-2.5#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 full product support, datasheet documentation, and manufacturing continuity for the LTC portfolio.
The LTC1550L series was designed specifically for low-noise, capacitor-based negative voltage generation in space-constrained portable RF systems - prioritizing ripple suppression, shutdown efficiency, and minimal external component count.
FAQ
What is the minimum input voltage required for the LTC1550LCMS8-2.5#PBF to deliver –2.5V at 20mA?
The LTC1550LCMS8-2.5#PBF requires a minimum VCC of 4.1V to maintain –2.5V output regulation at 20mA load, as specified in the Electrical Characteristics table under "VOUT Output Regulation" conditions. Below this, dropout occurs due to the N-channel pass device's headroom requirement.
Can the LTC1550LCMS8-2.5#PBF be used without the REG pin connected?
Yes - the REG pin is optional. If unused, leave it floating or tie it high via a pull-up resistor; it will not affect LTC1550LCMS8-2.5#PBF operation. However, omitting REG forfeits power-good monitoring capability for system-level fault detection.
Why does the LTC1550LCMS8-2.5#PBF require a moderate-ESR output capacitor instead of ultra-low-ESR types?
The LTC1550LCMS8-2.5#PBF's linear regulator feedback loop uses the ESR of the output capacitor to generate phase lead. Ultra-low-ESR capacitors (e.g., polymer or specialty ceramics) remove this zero, risking instability and oscillation. A 10µF tantalum or aluminum electrolytic (ESR ≈ 0.5–2Ω) is recommended, paralleled with 0.1µF ceramic.
Is the LTC1550LCMS8-2.5#PBF pin-compatible with the LTC1550LCS8-2.5#PBF?
No - the LTC1550LCMS8-2.5#PBF uses an 8-lead MSOP package with different pin spacing (0.65mm pitch) and footprint than the 8-lead SO package (1.27mm pitch) of the LTC1550LCS8-2.5#PBF. PCB layout and stencil must be redesigned for MSOP-8.
Does the LTC1550LCMS8-2.5#PBF support synchronization to an external clock?
No - the LTC1550LCMS8-2.5#PBF uses a fixed 900kHz internal oscillator and has no external clock input or sync capability. For synchronizable charge pumps, consider the LTC1429 or LTC1555/LTC1556 families instead of the LTC1550LCMS8-2.5#PBF.
LTC1550LCMS8-2.5#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:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.05V
- Voltage - Input (Max):
- 5.25V
- Voltage - Output (Min/Fixed):
- -2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 20mA
- Frequency - Switching:
- 900kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
LTC1550LCMS8-2.5#PBF FAQ
1.How can I place an order for LTC1550LCMS8-2.5#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1550LCMS8-2.5#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 LTC1550LCMS8-2.5#PBF reliable?
The price and inventory of LTC1550LCMS8-2.5#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1550LCMS8-2.5#PBF is usually 5 days.
3.What payment methods are accepted for LTC1550LCMS8-2.5#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1550LCMS8-2.5#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1550LCMS8-2.5#PBF?
LTC1550LCMS8-2.5#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1550LCMS8-2.5#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 LTC1550LCMS8-2.5#PBF?
For technical support, including LTC1550LCMS8-2.5#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1550LCMS8-2.5#PBF requirements.
6.How does Aetrix verify that LTC1550LCMS8-2.5#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1550LCMS8-2.5#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 LTC1550LCMS8-2.5#PBF meets industry standards.
7.What is the process for return or replacement of LTC1550LCMS8-2.5#PBF?
All LTC1550LCMS8-2.5#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1550LCMS8-2.5#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 LTC1550LCMS8-2.5#PBF part is unused and in its original packaging.
Return procedure for LTC1550LCMS8-2.5#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1550LCMS8-2.5#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…
