My Inquiry
My Account
Texas Instruments LM2687MM/NOPB
- Part No.:
- LM2687MM/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM2687MM/NOPB.pdf
- Description:
- IC REG CHRG PUMP ADJ 10MA 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,008
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2687MM/NOPB from Texas Instruments is a low-noise, regulated switched-capacitor voltage inverter IC that converts +2.7V to +5.5V input into an adjustable negative output from −1.5V to −5.2V, delivers up to 10mA, operates at 100 kHz typical switching frequency, and achieves 91% typical charge-pump efficiency - used for GaAsFET power amplifier bias in cellular handsets.
For engineers reviewing the LM2687MM/NOPB datasheet, LM2687MM/NOPB pinout, LM2687MM/NOPB application, or LM2687MM/NOPB equivalent, key selection criteria include regulated negative output adjustability, 1 mV typical output ripple, 0.05 µA shutdown current, MSOP-8 package compatibility, and feedback-based VOUT control via external resistor divider.
Technical Context
The LM2687MM/NOPB integrates a fixed-frequency (100 kHz) switched-capacitor inverter stage followed by a low-dropout linear regulator, enabling precise regulation of the inverted output while suppressing charge-pump ripple via high PSRR. Its architecture separates inversion (at VNEG) from regulation (at VOUT), decoupling noise generation from final output stability.
Feedback is implemented through a dedicated VFB pin referenced to −1.20 V, requiring an external resistor divider between VOUT and VADJ (0 V to VIN); the device does not support direct fixed-output variants and mandates external resistors for all output voltage settings. Shutdown is active-low, pulling both VOUT and VNEG to GND when asserted.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | +2.7 V to +5.5 V - supports single-cell Li-ion and dual-cell alkaline systems without external LDO pre-regulation. |
| Output Voltage Range | −1.5 V to −5.2 V - adjustable via external resistor divider on VFB pin; enables flexible biasing for diverse GaAsFET thresholds. |
| Max Output Current | 10 mA - sufficient for RF power amplifier bias in portable transceivers, not intended for rail-to-rail load switching. |
| Output Ripple | 1 mV (typical peak-to-peak) - achieved via PSRR filtering of charge-pump ripple by internal LDO stage. |
| Shutdown Current | 0.05 µA (typical) - enables ultra-low-power sleep modes in battery-operated handheld instrumentation. |
| Switching Frequency | 100 kHz (typical) - balances EMI suppression, capacitor size, and output resistance; fixed, not programmable. |
| Power Efficiency | 91% (typical at 10 mA) - minimizes thermal rise in space-constrained MSOP-8 package with no heatsink required. |
Pinout & Package
LM2687MM/NOPB is housed in an 8-pin MSOP (Mini Small Outline Package) with exposed die attach pad (DAP) not present - distinct from LLP variant. Pin numbering follows standard MSOP orientation with Pin 1 marked by dot or bevel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Cap+ | Charge pump flying capacitor positive terminal | Connects to C1+; internal switch node for charge transfer phase; requires low-ESR ceramic capacitor (≤0.3 Ω). |
| 2 - GND | Analog and power ground reference | Common return for VIN, VFB, SD, and VNEG; must be low-impedance plane to minimize noise coupling into VOUT. |
| 3 - Cap− | Charge pump flying capacitor negative terminal | Connects to C1−; complements Cap+ in charge-reversal cycle; shares same capacitor as Pin 1. |
| 4 - SD | Active-low shutdown control input | Logic-level compatible (VIH ≥ 2.2 V, VIL ≤ 0.5 V); asserts shutdown when pulled low, reducing IQ to 0.05 µA and grounding VOUT/VNEG. |
| 5 - VNEG | Unregulated negative output from charge pump | Raw inverted voltage before LDO regulation; not intended for direct load connection; feeds internal LDO input. |
| 6 - VFB | Regulator feedback input | Senses output via resistor divider; held at −1.20 V reference; determines VOUT via R1/R2 ratio; input bias current <100 nA. |
| 7 - VOUT | Regulated negative output voltage | Final stable output; supplies bias to RF amplifiers; PSRR attenuates switching ripple; max 10 mA continuous load. |
| 8 - VIN | Positive input supply | Accepts 2.7–5.5 V; powers both charge pump and LDO; bypass capacitor mandatory at pin for stability. |
Key Features
| Feature | Design Value |
|---|---|
| Regulated negative output via integrated LDO | Enables stable bias under varying load and input conditions without external regulation circuitry. |
| 1 mV typical output ripple | Meets stringent noise requirements for GaAsFET amplifier bias where supply-induced AM modulation degrades EVM. |
| 0.05 µA shutdown quiescent current | Extends battery life in standby mode for portable wireless devices without sacrificing fast wake-up (<600 µs start-up time). |
| MSOP-8 footprint with no exposed DAP | Reduces PCB area vs. SOIC-8 while maintaining manual solderability and compatibility with standard reflow profiles. |
| Fixed 100 kHz switching frequency | Optimizes capacitor sizing and EMI behavior without requiring frequency compensation or external clock synchronization. |
Applications
| Cellular Phone Power Amplifier Biasing | Interface Power Supplies |
|---|---|
Use Scenario: Providing clean negative gate bias to GaAsFET power amplifiers in GSM/UMTS/WCDMA handset front-ends. IC Role / Device Role / Timing Role: Regulated negative voltage source delivering stable −2.7 V to −3.8 V at ≤10 mA with sub-mV ripple. Use Value: Prevents AM-to-PM distortion and improves adjacent channel leakage ratio (ACLR) by eliminating switching noise coupling into RF signal path. |
Use Scenario: Generating isolated negative supply for RS-232 or LVDS interface ICs in handheld medical instruments. IC Role / Device Role / Timing Role: Compact, low-noise inverter supplying −3.3 V or −5 V from main 3.3 V or 5 V rail without inductors. Use Value: Eliminates need for bulky inductor-based DC/DC converters, enabling thinner form factors and lower BOM cost in portable diagnostics equipment. |
| Handheld Instrumentation | Laptop Computers and PDAs |
Use Scenario: Biasing precision op-amp input stages or ADC reference buffers requiring symmetrical dual supplies in field-portable test gear. IC Role / Device Role / Timing Role: Low-quiescent-current negative rail generator supporting sleep-mode operation with <0.1 µA system leakage. Use Value: Enables >100-hour battery runtime in multimeters and oscilloscope probes without compromising analog signal integrity. |
Use Scenario: Supplying negative bias to LCD panel driver ICs or smart-card interface controllers in legacy clamshell notebooks. IC Role / Device Role / Timing Role: Space-efficient inverter replacing discrete charge-pump + LDO solutions in constrained motherboard layouts. Use Value: Reduces component count by 4–6 parts per rail while maintaining ±1% output accuracy over temperature and line variation. |
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 |
|---|---|---|---|
| MAX680ESA+ | Unregulated inverter; no LDO stage; fixed −2×VIN output; higher ripple (15 mV); no VFB pin. | Suitable only where load tolerates unregulated output and ripple; cannot replace LM2687MM/NOPB in GaAsFET bias. | Select MAX680ESA+ only if cost sensitivity outweighs regulation requirement and output noise is non-critical. |
| TPS60403DBVR | Regulated inverter with adjustable output (−1.5 V to −5.5 V); 1.2 MHz switching; higher IQ (1.2 mA); SOT-23-6 package. | Better transient response but higher noise floor; unsuitable for ultra-low-IQ portable designs requiring <1 µA shutdown. | Choose TPS60403DBVR when board space is extremely limited and 1.2 MHz operation fits EMI profile; avoid for battery-life-critical bias rails. |
Compared with MAX680ESA+ and TPS60403DBVR, the LM2687MM/NOPB uniquely balances ultra-low shutdown current (0.05 µA), sub-mV ripple, and MSOP-8 manufacturability - making it optimal for cellular PA bias where noise, efficiency, and reliability are jointly constrained.
Availability
LM2687MM/NOPB is available at Aetrix Electronics and suitable for cellular phone power amplifier biasing, handheld instrumentation, and interface power supplies requiring stable component supply, long-term lifecycle support, and TI-authorized traceability.
Supply support for LM2687MM/NOPB 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
Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions across industrial, automotive, and personal electronics markets.
The LM2687MM/NOPB belongs to TI's precision power management portfolio, designed specifically for low-noise, low-current negative voltage generation in portable RF and instrumentation systems where inductor-free solutions are mandatory.
FAQ
What is the function of the VFB pin on the LM2687MM/NOPB?
The VFB pin on the LM2687MM/NOPB is the feedback input for the internal LDO regulator, referenced to a precise −1.20 V internal voltage. It must be connected to a resistor divider between VOUT and VADJ (typically GND) to set the regulated output voltage; leaving it unconnected will cause regulation failure and unstable VOUT.
Can the LM2687MM/NOPB operate from a 2.5 V input supply?
No - the LM2687MM/NOPB has a minimum operating input voltage of +2.7 V per its Absolute Maximum Ratings and Electrical Characteristics tables. At 2.5 V, the device will not start up or sustain regulation, and VOUT may collapse or become uncontrolled.
What is the maximum continuous output current specification for the LM2687MM/NOPB?
The LM2687MM/NOPB is rated for a maximum continuous output current of 10 mA at VOUT, as confirmed in both the General Description and Absolute Maximum Ratings sections of the datasheet. Exceeding this current risks thermal shutdown or output voltage droop beyond regulation limits.
Does the LM2687MM/NOPB require an external capacitor on the VNEG pin?
Yes - the LM2687MM/NOPB requires an output capacitor (C3, minimum 10 µF ceramic with ≤0.3 Ω ESR) connected directly between VNEG and GND to stabilize the charge-pump stage and reduce ripple before LDO regulation; omitting C3 causes excessive noise and potential oscillation.
Is the LM2687MM/NOPB pin-compatible with the LM2662 or LM2663?
No - the LM2687MM/NOPB has a unique 8-pin MSOP pinout including dedicated Cap+, Cap−, VFB, and VNEG pins; neither the LM2662 (8-pin SOIC, no VFB) nor LM2663 (8-pin SOIC, fixed −2×VIN) share the same pin configuration, functionality, or regulation architecture.
LM2687MM/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- 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):
- -1.5V
- Voltage - Output (Max):
- -5.2V
- Current - Output:
- 10mA
- Frequency - Switching:
- 110kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VSSOP
LM2687MM/NOPB FAQ
1.How can I place an order for LM2687MM/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2687MM/NOPB 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 LM2687MM/NOPB reliable?
The price and inventory of LM2687MM/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2687MM/NOPB is usually 5 days.
3.What payment methods are accepted for LM2687MM/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2687MM/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2687MM/NOPB?
LM2687MM/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2687MM/NOPB 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 LM2687MM/NOPB?
For technical support, including LM2687MM/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2687MM/NOPB requirements.
6.How does Aetrix verify that LM2687MM/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2687MM/NOPB 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 LM2687MM/NOPB meets industry standards.
7.What is the process for return or replacement of LM2687MM/NOPB?
All LM2687MM/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2687MM/NOPB, 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 LM2687MM/NOPB part is unused and in its original packaging.
Return procedure for LM2687MM/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2687MM/NOPB 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…
