My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX858CSA+T
- Part No.:
- MAX858CSA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX858CSA+T.pdf
- Description:
- IC REG BOOST PROG 125MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,500
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX858CSA+T from Maxim Integrated is a CMOS step-up DC-DC switching regulator optimized for low-input-voltage, battery-powered systems. It accepts 0.8V–VOUT input and delivers a pin-selectable 3.3V or 5V output with 125mA peak switch current limit, ±1.5% reference tolerance, and 25µA quiescent supply current - enabling extended runtime in glucose meters and 2-/3-cell portable instrumentation.
For engineers reviewing the MAX858CSA+T datasheet, MAX858CSA+T pinout, MAX858CSA+T application, or MAX858CSA+T equivalent, this page delivers verified circuit role (fixed-output boost converter), validated package (8-pin SO), confirmed pin functions (e.g., 3/5 select, LBI/LBO low-battery detection), and real-world design constraints including 0.8V start-up voltage and 47µH inductor compatibility.
Technical Context
The MAX858CSA+T implements a minimum-off-time, current-limited pulse-frequency modulation (PFM) control scheme without an oscillator - switching frequency varies with load and input voltage up to 500kHz. Its internal N-channel sense-FET has ~4Ω on-resistance and 125mA ±25mA fixed peak current limit, enabling use of small, low-cost inductors while maintaining >85% efficiency at 100mA.
It integrates a precision 1.25V reference (±1.5% over temperature), low-battery comparator (1.25V threshold with 25mV hysteresis), and bootstrap power architecture where OUT supplies internal circuitry - allowing operation down to 0.8V input after startup and supporting output-follows-battery behavior when VIN exceeds VOUT.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Pin-selectable 3.3V or 5V - no external feedback resistors required; logic-level 3/5 pin ties to GND (5V) or OUT (3.3V). |
| Input Voltage Range | 0.8V to VOUT - supports single-cell alkaline/NiMH (0.8V cutoff) and enables deep battery discharge utilization. |
| Peak Switch Current | 125mA ±25mA - sets inductor saturation margin and maximum output current (e.g., 35mA at 3.3V with 2.5V input). |
| Quiescent Supply Current | 25µA in active mode - directly extends battery life in always-on medical sensors and data loggers. |
| Shutdown Current | 1µA - reduces system standby drain to negligible levels during sleep cycles. |
| Reference Voltage | 1.25V ±1.5% over -40°C to +85°C - stable bias source for external ADCs or comparator circuits. |
| Start-Up Voltage | 0.8V typical - ensures reliable turn-on even with heavily depleted batteries. |
Pinout & Package
MAX858CSA+T is housed in an 8-pin SO (Small Outline) package per JEDEC MS-012, with 1.27mm lead pitch, 4.9mm × 6.0mm body, and exposed pad not present. Pin 1 is marked by beveled corner; device orientation follows standard SO top-view labeling.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - SHDN | Active-low shutdown control | Pulls entire regulator into 1µA sleep state; unclamped - tolerates up to 7V regardless of VOUT. |
| 2 - 3/5 | Output voltage select | Connect to GND for 5V output; connect to OUT for 3.3V output - internally diode-clamped to GND and OUT. |
| 3 - REF | Precision 1.25V reference output | Sources/sinks ±250µA/20µA; requires 0.22µF bypass to GND if loaded; used for external monitoring or feedback. |
| 4 - LX | Switch node | Drain of internal N-MOSFET; connects to inductor and Schottky diode anode - high dv/dt node requiring short PCB traces. |
| 5 - GND | Power ground | Low-impedance return path; must solder directly to solid ground plane to minimize noise and maximize efficiency. |
| 6 - OUT | Regulated output & bootstrap supply | Delivers 3.3V/5V output; also powers internal circuitry - enables operation below VOUT after startup. |
| 7 - LBI | Low-battery input | Comparator input referenced to 1.25V; threshold set by external resistor divider; <100nA bias current allows high-value resistors. |
| 8 - LBO | Open-drain low-battery output | Sinks current when LBI < 1.25V; requires external pull-up (e.g., to OUT); drives microcontroller interrupt or LED indicator. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 25µA active / 1µA shutdown - minimizes battery depletion in intermittent-use medical devices like glucose meters. |
| 0.8V start-up capability | Enables operation from deeply discharged single-cell batteries - critical for long-life portable instrumentation. |
| Integrated low-battery detector | LBI/LBO pair with 1.25V threshold and 25mV hysteresis - eliminates need for external supervisor IC in space-constrained designs. |
| Fixed-output architecture | No external feedback resistors required - reduces BOM count and layout complexity versus adjustable regulators. |
| High-efficiency PFM control | 85%+ efficiency at 100mA with 47µH inductor - achieves optimal power density without PWM EMI concerns. |
Applications
| Glucose Meters | Portable Data Collectors |
|---|---|
Use Scenario: Battery-powered handheld device measuring blood glucose concentration with LCD display and wireless transmission. IC Role / Device Role / Timing Role: Step-up regulator generating stable 3.3V rail for MCU, sensor interface, and RF transceiver from 1.5–3.0V alkaline cells. Use Value: 0.8V start-up and 25µA quiescent current extend usable battery life beyond 500 measurements per set of AA cells. |
Use Scenario: Ruggedized field instrument capturing environmental sensor data (temperature, humidity, CO₂) and storing to flash memory. IC Role / Device Role / Timing Role: Fixed 5V boost converter powering analog front-end, ADC, and microSD card interface from two NiMH cells (2.4V nominal). Use Value: 125mA peak switch limit and integrated LBI/LBO enable compact, self-monitoring power stage with no external supervision components. |
| Palmtop Computers | Medical Instrumentation |
Use Scenario: Legacy handheld computing device with monochrome LCD, keyboard, and serial connectivity operating from two AAA cells. IC Role / Device Role / Timing Role: 3.3V supply generator for CPU core and I/O rails, using 3/5 pin to select voltage mode based on system configuration. Use Value: Pin-selectable output eliminates firmware dependency for voltage setting - simplifies production programming and field upgrades. |
Use Scenario: Portable ECG monitor with analog signal conditioning, 12-bit ADC, and Bluetooth LE module powered by coin-cell or button battery. IC Role / Device Role / Timing Role: High-efficiency boost converter delivering regulated 3.3V from 1.8–2.2V input, with LBO signaling end-of-life battery condition to host MCU. Use Value: ±1.5% reference tolerance ensures accurate ADC reference scaling across temperature, improving diagnostic measurement repeatability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output boost converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS61200DRCT | 1.8V–5.5V input; 3.3V/5V selectable via FB resistor; 1.2A switch current; 1.2MHz fixed-frequency PWM. | Higher output current but higher quiescent current (50µA vs. 25µA); requires external feedback network for voltage selection. | Choose for higher-power loads (>100mA) where EMI filtering is feasible; avoid when ultra-low IQ or pin-select simplicity is mandatory. |
| LT1944ES5#TRMPBF | 0.9V–5.5V input; fixed 3.3V output only; 600mA switch current; 1.1MHz PWM; integrated Schottky. | Single-output-only; no 5V option or LBI/LBO; higher IQ (110µA); requires external inductor but no external diode. | Choose when 3.3V-only operation suffices and board space is constrained; avoid when dual-voltage flexibility or battery monitoring is needed. |
Compared with TPS61200DRCT and LT1944ES5#TRMPBF, MAX858CSA+T uniquely combines pin-selectable 3.3V/5V output, 0.8V start-up, integrated low-battery detection, and 25µA quiescent current - making it optimal for cost-sensitive, battery-life-critical medical and portable instrumentation where minimal external components are essential.
Availability
MAX858CSA+T is available at Aetrix Electronics and suitable for glucose meters, portable data collectors, and palmtop computers requiring stable component supply with guaranteed long-term availability and full traceability.
Supply support for MAX858CSA+T 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 precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.
MAX858CSA+T belongs to the MAX856–MAX859 family of ultra-low-IQ step-up regulators engineered specifically for battery-powered portable instrumentation where start-up voltage, efficiency, and integration of battery monitoring are critical.
FAQ
What is the minimum input voltage required to start up the MAX858CSA+T?
The MAX858CSA+T has a typical start-up input voltage of 0.8V, enabling reliable turn-on from deeply discharged single-cell alkaline or NiMH batteries. This value is production-tested and remains valid across the full operating temperature range (-40°C to +85°C). Once started, the device continues regulating down to 0.8V input due to its bootstrap architecture powered from the OUT pin.
How does the 3/5 pin select between 3.3V and 5V output on the MAX858CSA+T?
On the MAX858CSA+T, the 3/5 pin selects output voltage via direct logic connection: tie to GND for 5V output, or tie to the OUT pin for 3.3V output. The pin is internally diode-clamped to both GND and OUT, so no external protection is needed. This eliminates external resistors and firmware configuration, simplifying design for dual-voltage systems like portable instruments with interchangeable peripherals.
Can the MAX858CSA+T drive a 100mA load at 3.3V output?
No - the MAX858CSA+T has a 125mA peak switch current limit and is rated for up to 35mA continuous output at 3.3V with 2.5V input (per Typical Operating Characteristics curves). At 100mA, the device would exceed safe thermal limits and cause regulation failure. For 100mA loads, the MAX856CSA+T (500mA switch limit) is the appropriate variant within the same family.
What is the function of the LBI and LBO pins on the MAX858CSA+T?
The LBI (Low-Battery Input) and LBO (Low-Battery Output) pins implement an integrated battery monitor: LBI compares input voltage against the internal 1.25V reference, and when it falls below threshold, LBO - an open-drain N-channel MOSFET - sinks current to GND. This allows direct connection to a microcontroller GPIO or LED without external components, providing system-level battery health awareness in glucose meters and portable diagnostics.
Which inductor value is recommended for use with the MAX858CSA+T?
A 47µH inductor is recommended for the MAX858CSA+T, as validated in Maxim's Typical Operating Circuit and supported by efficiency curves. The inductor's incremental saturation current must exceed 125mA (the device's peak switch limit), and DC resistance should be minimized to preserve efficiency. Surface-mount types like Sumida CDR105B-470 or Murata LQH4N470 meet these requirements and fit standard SO-package layouts.
MAX858CSA+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Output Type:
- Programmable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 0.8V
- Voltage - Input (Max):
- 6V
- Voltage - Output (Min/Fixed):
- 3.3V, 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 125mA (Switch)
- Frequency - Switching:
- 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX858CSA+T FAQ
1.How can I place an order for MAX858CSA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX858CSA+T 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 MAX858CSA+T reliable?
The price and inventory of MAX858CSA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX858CSA+T is usually 5 days.
3.What payment methods are accepted for MAX858CSA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX858CSA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX858CSA+T?
MAX858CSA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX858CSA+T 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 MAX858CSA+T?
For technical support, including MAX858CSA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX858CSA+T requirements.
6.How does Aetrix verify that MAX858CSA+T is sourced from the original manufacturer or authorized distributors?
All MAX858CSA+T 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 MAX858CSA+T meets industry standards.
7.What is the process for return or replacement of MAX858CSA+T?
All MAX858CSA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX858CSA+T, 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 MAX858CSA+T part is unused and in its original packaging.
Return procedure for MAX858CSA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX858CSA+T 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…
