My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX861CSA+
- Part No.:
- MAX861CSA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX861CSA+.pdf
- Description:
- IC REG CHARG PUMP INV 50MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,446
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX861CSA+ from Maxim Integrated is a frequency-selectable, 50mA switched-capacitor voltage inverter/doubler IC that operates from +1.5V to +5.5V (inverter) or +2.5V to +5.5V (doubler), delivers ±90% efficiency at 50mA, features three user-selectable switching frequencies (13/100/250 kHz), and targets low-noise, inductorless power conversion in portable medical instruments and handheld test equipment.
For engineers reviewing the MAX861CSA+ datasheet, MAX861CSA+ pinout, MAX861CSA+ application, or MAX861CSA+ equivalent, this page provides verified functional identity, validated pin roles, confirmed operating modes (inverter/doubler), exact switching-frequency mapping per FC pin state, and real-world design implications of 12Ω output resistance and 1µA shutdown current.
Technical Context
The MAX861CSA+ implements a BiCMOS charge-pump architecture with direct oscillator-to-switch coupling (no frequency division), enabling precise control of 13/100/250 kHz switching via FC pin states (VDD, GND, OUT). Its LV pin configures mode: grounded for inverting operation, connected to OUT for doubling - no internal regulation, but stable output under load due to 12Ω effective source resistance.
Shutdown is active-low on SHDN, reducing supply current to <1µA; startup requires input supply capable of delivering ≥90mA peak transient current. Output voltage droop is predictable: e.g., -5.0V no-load drops to -4.4V at 50mA with 12Ω ROUT, directly calculable from VOUT = -VIN − IOUT × ROUT in inverter mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 50mA continuous - supports rail-splitting for dual-supply op-amps without inductors. |
| Switching Frequencies | 13kHz (FC=VDD), 100kHz (FC=GND), 250kHz (FC=OUT) - selects capacitor size vs. EMI trade-off. |
| Efficiency | 87% at 50mA load - enables battery life extension in portable medical devices. |
| Quiescent Current | 200µA typical - minimizes standby drain in always-on instrumentation. |
| Shutdown Current | <1µA - critical for long-term battery-powered deployments. |
| Output Resistance | 12Ω - defines voltage droop: ΔV = 50mA × 12Ω = 0.6V at full load. |
| Input Voltage Range | +1.5V to +5.5V (inverter), +2.5V to +5.5V (doubler) - compatible with single-cell Li-ion and 3.3V/5V rails. |
Pinout & Package
MAX861CSA+ is housed in an 8-pin SO package (SOIC-8, 150mil width), RoHS-compliant, with standard 1.27mm pitch and JEDEC MS-012AC outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD (Pin 8) | Positive input supply | Accepts +1.5V to +5.5V; powers internal oscillator and switches. |
| SHDN (Pin 7) | Active-low shutdown control | Pull low to disable all switching; draws <1µA; connect to VDD to enable. |
| OUT (Pin 5) | Inverted or doubled output | Delivers -VIN (LV=GND) or +2×VIN (LV=OUT); 50mA sink/source capability. |
| LV (Pin 6) | Mode selection | GND → inverter; OUT → doubler; determines input voltage range and output polarity. |
| FC (Pin 1) | Frequency control | VDD → 13kHz, GND → 100kHz, OUT → 250kHz - sets noise spectrum and capacitor sizing. |
| C1+ (Pin 2) | Flying capacitor positive terminal | Drives charge transfer cycle; connects to one side of flying cap C1. |
| GND (Pin 3) | Ground reference | Common return for VDD, OUT, and external capacitors; must be low-impedance. |
| C1− (Pin 4) | Flying capacitor negative terminal | Completes flying cap path; alternates polarity with C1+ during switching. |
Key Features
| Feature | Design Value |
|---|---|
| Invert or double input voltage | Single IC supports both topologies via LV pin - eliminates need for separate inverter/doubler parts. |
| Three selectable switching frequencies | 13/100/250 kHz options allow EMI avoidance in sensitive analog circuits (e.g., ECG front-ends). |
| High-frequency reduces capacitor size | At 250kHz, 2.2µF flying caps suffice - cuts board area vs. 68µF needed at 13kHz. |
| 87% efficiency at 50mA | Enables >100-hour runtime on two AA cells powering 50mA analog signal chains. |
| 1µA shutdown supply current | Permits micro-power sleep modes in portable diagnostics without external load switches. |
Applications
| Portable Medical Sensors | Handheld Test Equipment |
|---|---|
|
Use Scenario: Powering dual-rail op-amps in battery-operated ECG or pulse oximeter front-ends requiring ±2.5V from a single 3.3V Li-ion cell. IC Role / Device Role / Timing Role: Inverter mode (LV=GND) generating clean -3.3V rail; FC=GND selects 100kHz to avoid interference with 50Hz mains pickup. Use Value: Eliminates inductors and reduces EMI-sensitive layout area by 40% vs. inductive DC/DC, while maintaining 0.6V max droop at 50mA sensor bias current. |
Use Scenario: Generating ±5V rails for precision ADC drivers and DAC buffers in field-deployable multimeters. IC Role / Device Role / Timing Role: Cascaded MAX861CSA+ units (Figure 1) producing -10V from +5V input; LV=GND on both stages. Use Value: Achieves -10V @ 25mA with <1.2V droop using only four 10µF ceramic caps - avoids custom transformer-based supplies. |
| Interface Power Supplies | Operational-Amplifier Power Supplies |
|
Use Scenario: Providing isolated negative bias for RS-232 transceivers in industrial PLC I/O modules powered from 24V DC. IC Role / Device Role / Timing Role: Doubler mode (LV=OUT) generating +10V from +5V logic rail; FC=VDD sets 13kHz for lowest quiescent current. Use Value: Delivers 10V @ 20mA with 200µA no-load draw - extends system uptime during brownout conditions. |
Use Scenario: Splitting +5V into ±2.5V for rail-to-rail op-amps in audio preamplifiers within portable ultrasound probes. IC Role / Device Role / Timing Role: Inverter mode (LV=GND); FC=OUT selects 250kHz to minimize 10µF reservoir cap size and ripple. Use Value: Reduces output ripple to <15mVpp at 50mA while fitting within 3mm² PCB area budget - meets SNR >95dB requirement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switched-capacitor voltage converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX860CSA+ | Same 8-pin SO package and pinout; switching frequencies 6/50/130 kHz (lower range); 200µA quiescent current identical. | Better suited for ultra-low-noise 6kHz operation in seismic sensors; less suitable for EMI-sensitive 100–250kHz bands. | Select MAX860CSA+ when lowest possible fundamental switching noise is required and 50mA load is acceptable. |
| MAX660CPA+ | 100mA output, 6.5Ω output resistance, fixed 5/40kHz frequencies, no FC or LV pins; 8-pin PDIP/SO. | Higher current and lower ROUT support heavier loads (e.g., LCD bias), but lacks frequency selectivity and mode flexibility. | Choose MAX660CPA+ when >50mA output or lower output impedance is mandatory and EMI constraints allow fixed low-frequency operation. |
Compared with MAX860CSA+, MAX861CSA+ offers higher-frequency options (up to 250kHz) for tighter EMI control and smaller capacitors, while MAX660CPA+ provides greater output current and lower ROUT at the cost of configurability and higher quiescent current - making MAX861CSA+ optimal for space-constrained, noise-sensitive 50mA applications.
Availability
MAX861CSA+ is available at Aetrix Electronics and suitable for portable medical sensors, handheld test equipment, interface power supplies, operational-amplifier power supplies, and portable computers requiring stable component supply across industrial temperature ranges (-40°C to +85°C).
Supply support for MAX861CSA+ 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
Maxim Integrated (now part of Analog Devices) designs high-performance analog and mixed-signal ICs for power management, sensing, and communication applications, with emphasis on reliability and integration for demanding environments.
The MAX860/MAX861 product line delivers compact, inductorless voltage conversion for battery-powered instrumentation, targeting designers needing configurable, low-EMI, 50mA charge-pump solutions where board space and electromagnetic compatibility are critical.
FAQ
What is the function of the LV pin on the MAX861CSA+?
The LV pin on the MAX861CSA+ selects operating mode: connecting LV to GND configures the device as a voltage inverter (output = -VIN), while connecting LV to OUT configures it as a voltage doubler (output = +2×VIN). This pin directly determines the valid input voltage range (+1.5V to +5.5V for inverter, +2.5V to +5.5V for doubler) and must not be left floating. The MAX861CSA+ datasheet specifies these connections as mandatory for correct functionality.
How does the FC pin affect switching frequency in the MAX861CSA+?
The FC pin on the MAX861CSA+ sets one of three discrete switching frequencies: FC = VDD yields 13kHz, FC = GND yields 100kHz, and FC = OUT yields 250kHz. These frequencies are device-specific to MAX861 (vs. MAX860's 6/50/130kHz) and directly impact capacitor sizing, output ripple, and EMI profile. No external components are needed - frequency selection is purely logic-level driven per the MAX861CSA+ pin configuration table.
Can the MAX861CSA+ be used as a direct replacement for the ICL7660?
The MAX861CSA+ is not a pin-compatible drop-in replacement for the ICL7660 due to differing pin functions: ICL7660 uses OSC (pin 1) as an oscillator output, while MAX861CSA+ uses FC (pin 1) as a frequency-control input. To retrofit, pin 7 (SHDN) must be tied to VDD to enable operation, and FC may require re-routing. The MAX861CSA+ offers higher frequency options and lower quiescent current but requires minor board modifications.
What is the maximum continuous output current specification for the MAX861CSA+?
The MAX861CSA+ is rated for 50mA continuous output current under specified thermal conditions (TA ≤ +85°C, SO package). Absolute maximum rating allows 60mA briefly, but sustained operation above 50mA risks exceeding thermal limits and degrading efficiency or reliability. Designers must verify junction temperature using the SO package's 5.88mW/°C derating factor above +70°C, as documented in the MAX861CSA+ absolute maximum ratings table.
Does the MAX861CSA+ include internal voltage regulation?
No, the MAX861CSA+ does not include internal voltage regulation. Its output voltage is unregulated and follows VOUT ≈ -VIN (inverter) or VOUT ≈ +2×VIN (doubler), with droop determined by load current and output resistance (12Ω typical). For example, with VIN = +5V and 50mA load, VOUT drops to approximately -4.4V. Regulation must be implemented externally if tight output tolerance is required, as explicitly stated in the MAX861CSA+ detailed description section.
MAX861CSA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Ratiometric
- Output Configuration:
- Positive or Negative
- Topology:
- Charge Pump
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.5V, 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- -Vin, 2Vin
- Voltage - Output (Max):
- -
- Current - Output:
- 50mA
- Frequency - Switching:
- 13kHz, 100kHz, 250kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX861CSA+ FAQ
1.How can I place an order for MAX861CSA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX861CSA+ 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 MAX861CSA+ reliable?
The price and inventory of MAX861CSA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX861CSA+ is usually 5 days.
3.What payment methods are accepted for MAX861CSA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX861CSA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX861CSA+?
MAX861CSA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX861CSA+ 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 MAX861CSA+?
For technical support, including MAX861CSA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX861CSA+ requirements.
6.How does Aetrix verify that MAX861CSA+ is sourced from the original manufacturer or authorized distributors?
All MAX861CSA+ 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 MAX861CSA+ meets industry standards.
7.What is the process for return or replacement of MAX861CSA+?
All MAX861CSA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX861CSA+, 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 MAX861CSA+ part is unused and in its original packaging.
Return procedure for MAX861CSA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX861CSA+ 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…
