My Inquiry
My Account
Analog Devices Inc. LTC1550LCS8#TRPBF
- Part No.:
- LTC1550LCS8#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1550LCS8#TRPBF.pdf
- Description:
- IC REG CHARGE PUMP ADJ 20MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,702
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1550LCS8#TRPBF from Analog Devices (formerly Linear Technology) is a low-noise, switched-capacitor regulated negative voltage inverter with integrated linear post-regulator, delivering –2V output at up to 20mA load current with <1mVP-P ripple. It operates from a single 2.7V–5.25V supply, features active-low TTL-compatible shutdown (SHDN), and is optimized for GaAs FET bias generation in portable RF transmitters.
For engineers reviewing the LTC1550LCS8#TRPBF datasheet, LTC1550LCS8#TRPBF pinout, LTC1550LCS8#TRPBF application, or LTC1550LCS8#TRPBF equivalent, key selection criteria include guaranteed ±2.5% output regulation over line/load/temperature, 900kHz charge pump frequency enabling compact 0.1µF external capacitors, and MSOP-8 package compatibility with space-constrained portable designs.
Technical Context
The LTC1550LCS8#TRPBF integrates an inverting switched-capacitor charge pump (900kHz oscillator, C1+/C1–/CPOUT pins) followed by a negative linear regulator (VOUT, REG, GND) that suppresses switching artifacts. Its internal N-channel pass device enables low dropout-maintaining regulation down to 2.7V input for –2V output.
Shutdown control is implemented via an active-low SHDN pin drawing only 0.2µA in sleep mode; the device requires no external pull-up resistor on SHDN due to internal design. Output voltage is fixed at –2V using internal resistor divider, eliminating need for ADJ pin or external feedback resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed –2.0V with ±2.5% regulation over line, load (0–20mA), and temperature (0°C to 70°C) |
| Output Ripple | <1mVP-P typical with 10µF COUT + 0.1µF ceramic bypass-critical for noise-sensitive RF bias rails |
| Supply Range | 2.7V to 5.25V; minimum VCC = 3.1V required for full 10mA load at –2V output |
| Quiescent Current | 3.65mA typical at 5V supply; drops to 0.2µA in shutdown-enables battery life extension |
| Charge Pump Freq | 900kHz internal oscillator-avoids IF bands (400–600kHz), allows use of small 0.1µF ceramic flying capacitors |
| Shutdown Input | TTL-compatible active-low SHDN pin; valid logic high ≥2V, logic low ≤0.8V at VCC = 5V |
| Max Output Current | 20mA guaranteed when VCC ≥ 3.75V; derates below that due to internal pass device headroom |
Pinout & Package
Package: 8-lead MSOP (MS8), 3.0mm × 3.0mm × 0.85mm body, exposed pad not connected. Pin pitch: 0.65mm. RoHS-compliant, halogen-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (REG) | Power Good Open-Drain Output | Pulls low when VOUT is within ±5% of –2V; requires external pull-up to monitor regulation status |
| 2 (CPOUT) | Negative Charge Pump Output | Intermediate node supplying linear regulator input; requires 0.1µF capacitor to GND with star-grounded layout |
| 3 (GND) | Analog Ground Reference | Common return for linear regulator feedback and charge pump; must connect directly to PCB ground plane |
| 4 (C1–) | Flying Capacitor Negative Terminal | Connects to negative side of 0.1µF charge pump capacitor (C1); forms half of charge transfer path |
| 5 (SHDN) | Active-Low Shutdown Control | Drives internal charge pump and regulator into ultra-low-power state (<0.2µA ICC) when pulled low |
| 6 (VCC) | Positive Supply Input | Accepts 2.7V–5.25V; requires ≥2.2µF low-ESR ceramic bypass capacitor placed adjacent to pin |
| 7 (C1+) | Flying Capacitor Positive Terminal | Connects to positive side of 0.1µF charge pump capacitor (C1); switches between VCC and GND during pumping cycle |
| 8 (VOUT) | Regulated Negative Output | Delivers –2V; requires ≥10µF output capacitor (tantalum + 0.1µF ceramic) for stability and ripple suppression |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Linear Post-Regulator | Reduces charge pump ripple to <1mVP-P, enabling direct use in RF bias without additional filtering |
| 900kHz Switching Frequency | Permits use of standard 0.1µF ceramic flying capacitors-no specialized high-voltage or low-ESR parts needed |
| Ultra-Low Shutdown Current | 0.2µA typical ICC in shutdown-preserves battery charge during idle periods in portable systems |
| Fixed –2V Output | Eliminates external feedback resistors and ADJ pin routing; simplifies layout and reduces BOM count |
| Single-Supply Operation | Generates regulated negative rail from 2.7V–5.25V positive source-removes need for dual supplies in RF front-ends |
Applications
| Portable Cellular Transmitter Bias | GaAs FET Power Amplifier Supply |
|---|---|
Use Scenario: Providing stable gate bias voltage to GaAs FETs in GSM/EDGE handset power amplifiers operating from single-cell Li-ion battery. IC Role / Device Role / Timing Role: Regulated –2V negative bias generator replacing discrete charge pump + LDO solutions. Use Value: Enables 3.7V nominal battery to deliver precise –2V bias with <1mVP-P noise-prevents AM-to-PM distortion in PA stage. | Use Scenario: Generating clean negative supply for gate control in 2.4GHz Wi-Fi/BT combo modules with integrated GaAs PAs. IC Role / Device Role / Timing Role: Low-noise inverted voltage source synchronized to RF transmit bursts via SHDN pin. Use Value: 0.2µA shutdown current extends standby time; 900kHz switching avoids interference with 2.4GHz ISM band harmonics. |
| Low-Noise RF Front-End Bias | Battery-Powered Instrumentation |
Use Scenario: Supplying bias to low-noise amplifier (LNA) stages in handheld spectrum analyzers or RF test probes. IC Role / Device Role / Timing Role: Ultra-low-ripple negative rail generator for analog signal chain reference points. Use Value: <1mVP-P output ripple ensures sub-mV baseline stability-critical for high-dynamic-range measurements. | Use Scenario: Creating isolated negative supply for op-amp rails in portable medical sensors (e.g., ECG front-end) powered by coin-cell batteries. IC Role / Device Role / Timing Role: Micropower inverting regulator supporting intermittent measurement cycles. Use Value: 3.65mA quiescent current at 3.3V input enables >100-hour operation on CR2032; shutdown extends life further. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar negative voltage inverter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1550LCMS8-2 | Same die, identical electrical specs; differs only in tape-and-reel packaging (TRPBF vs TR) | No functional difference; both rated for 0°C to 70°C commercial temp range | Select LTC1550LCS8#TRPBF for verified RoHS-compliant, lead-free, halogen-free reel delivery |
| LTC1551LCS8-2 | Pin-compatible variant with active-high SHDN (vs active-low on LTC1550LCS8#TRPBF) | Requires inverted control logic; otherwise identical –2V output, ripple, and regulation performance | Choose LTC1551LCS8-2 only if system MCU GPIO drives high to enable-no hardware redesign needed |
Compared with LTC1550LCMS8-2, LTC1550LCS8#TRPBF offers identical regulation and noise performance but with certified lead-free packaging; versus LTC1551LCS8-2, it provides active-low shutdown control-simplifying interface with microcontrollers lacking open-drain outputs.
Availability
LTC1550LCS8#TRPBF is available at Aetrix Electronics and suitable for portable RF transmitters, GaAs FET bias generators, and battery-powered instrumentation requiring stable component supply, low-noise negative voltage generation, and RoHS-compliant packaging.
Supply support for LTC1550LCS8#TRPBF 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, documentation, and manufacturing continuity for legacy Linear parts including the LTC series.
The LTC1550L family was designed specifically for low-noise, micropower negative voltage generation in portable wireless infrastructure-emphasizing ripple suppression, shutdown efficiency, and minimal external component count.
FAQ
What is the maximum output current capability of the LTC1550LCS8#TRPBF at –2V output?
The LTC1550LCS8#TRPBF delivers up to 20mA at –2V output when supplied with VCC ≥ 3.75V. At lower input voltages-such as 3.1V-the maximum guaranteed load drops to 10mA, and at 2.7V it is limited to 5mA. These limits are defined by the internal N-channel pass device's headroom requirements and are fully specified in the Electrical Characteristics table across temperature and line conditions.
Does the LTC1550LCS8#TRPBF require external feedback resistors to set its output voltage?
No, the LTC1550LCS8#TRPBF does not require external feedback resistors. It is the fixed –2V version of the LTC1550L family and uses an internal resistor divider to set the output. The ADJ pin is absent in this 8-pin MSOP variant-only present in the 16-pin SSOP adjustable versions. This eliminates layout complexity and BOM cost associated with external resistor networks.
How does the REG pin on the LTC1550LCS8#TRPBF function, and what external components are needed?
The REG pin on the LTC1550LCS8#TRPBF is an open-drain output that pulls low when VOUT is within ±5% of –2V. To use it, an external pull-up resistor (typically 10kΩ to VCC or another logic rail) is required. Without pull-up, REG remains floating and cannot indicate regulation status. The pin can safely be pulled up to 6V and sinks up to 4mA-making it compatible with 3.3V or 5V monitoring logic.
Can the LTC1550LCS8#TRPBF operate from a 3.3V supply while delivering –2V at 10mA?
Yes, the LTC1550LCS8#TRPBF can operate from a 3.3V supply while delivering –2V at 10mA. The datasheet guarantees this performance for VCC ≥ 3.1V under 10mA load. At 3.3V, the device maintains ±2.5% output regulation across 0°C to 70°C, with typical output ripple remaining below 1mVP-P when using recommended 10µF + 0.1µF output capacitance.
What is the purpose of the CPOUT pin on the LTC1550LCS8#TRPBF, and how must it be decoupled?
The CPOUT pin on the LTC1550LCS8#TRPBF is the negative output of the internal charge pump stage, feeding the linear regulator. It must be decoupled with a 0.1µF ceramic capacitor connected directly to GND, with the capacitor's ground trace tied to the same GND pin used by the VCC bypass cap-forming a star ground. This minimizes AC current loop area and prevents coupling of switching noise into the regulated output.
LTC1550LCS8#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- 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):
- 5.5V
- Voltage - Output (Min/Fixed):
- -1.225V
- Voltage - Output (Max):
- -4.8V
- 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-SO
LTC1550LCS8#TRPBF FAQ
1.How can I place an order for LTC1550LCS8#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1550LCS8#TRPBF 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 LTC1550LCS8#TRPBF reliable?
The price and inventory of LTC1550LCS8#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1550LCS8#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1550LCS8#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1550LCS8#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1550LCS8#TRPBF?
LTC1550LCS8#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1550LCS8#TRPBF 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 LTC1550LCS8#TRPBF?
For technical support, including LTC1550LCS8#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1550LCS8#TRPBF requirements.
6.How does Aetrix verify that LTC1550LCS8#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1550LCS8#TRPBF 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 LTC1550LCS8#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1550LCS8#TRPBF?
All LTC1550LCS8#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1550LCS8#TRPBF, 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 LTC1550LCS8#TRPBF part is unused and in its original packaging.
Return procedure for LTC1550LCS8#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1550LCS8#TRPBF 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…
