My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX6138AEXR33
- Part No.:
- MAX6138AEXR33
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Voltage Reference
- Package:
- SC-70, SOT-323
- Datasheet:
-
MAX6138AEXR33.pdf
- Description:
- VOLTAGE REFERENCE
- Quantity:
- Payment:
- Shipping:
Inventory:1,120
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX6138AEXR33 from Maxim Integrated is a precision two-terminal shunt-mode bandgap voltage reference with a fixed 3.3000V reverse breakdown voltage, 0.1% initial accuracy, and 25ppm/°C max temperature coefficient over –40°C to +85°C - used for high-stability analog-to-digital conversion, portable power monitoring, and precision sensor biasing in space-constrained designs.
For engineers reviewing the MAX6138AEXR33 datasheet, MAX6138AEXR33 pinout, MAX6138AEXR33 application, or MAX6138AEXR33 equivalent, key selection criteria include its SC70-3 package footprint, 60µA–15mA shunt-current range, 50µVRMS wideband noise (10Hz–10kHz), no-output-capacitor operation, and guaranteed stability with capacitive loads.
Technical Context
The MAX6138AEXR33 implements a laser-trimmed BiCMOS bandgap core delivering stable 3.3V output across 60µA–15mA shunt current and –40°C to +85°C ambient. Its dynamic impedance remains ≤0.8Ω at 1mA/120Hz, enabling low-noise regulation under varying load conditions.
Unlike series references, it operates as a two-terminal shunt device requiring only an external source resistor (RS) to set operating current - simplifying bias design while maintaining ±0.1% output tolerance without external compensation components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 3.3000V ±0.0033V at +25°C - ensures 12-bit ADC reference accuracy without trimming. |
| Initial Accuracy | ±0.1% - guarantees absolute voltage error ≤±3.3mV at room temperature. |
| Temp Coefficient | ≤25ppm/°C - limits drift to ≤±0.825mV over full –40°C to +85°C range. |
| Shunt Current Range | 60µA to 15mA - supports ultra-low-power sensing and high-current DAC reference use cases. |
| Output Noise | 50µVRMS (10Hz–10kHz) - enables <16-bit effective resolution in precision measurement systems. |
| Dynamic Impedance | ≤0.8Ω at 1mA/120Hz - maintains voltage stability during fast load transients. |
| Long-Term Stability | 120ppm after 1000h - ensures minimal calibration drift in field-deployed instrumentation. |
Pinout & Package
MAX6138AEXR33 is housed in a 3-pin SC70-3 surface-mount package (1.8mm × 1.8mm × 0.9mm), 50% smaller than SOT23 equivalents. Pin 3 is NC and must be left floating or tied to Pin 2.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (+) | Anode / Positive Terminal | Connects to regulated output node; sinks shunt current when reverse-biased. |
| Pin 2 (–) | Cathode / Negative Terminal | Reference ground return path; forms voltage node with Pin 1 for 3.3V regulation. |
| Pin 3 (N.C.) | No Connection | Must remain unconnected or shorted to Pin 2 - no internal function or signal routing. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-small SC70-3 package | 1.8mm × 1.8mm footprint - reduces PCB area by 50% vs. SOT23, critical for wearables and IoT sensors. |
| No output capacitor required | Internally compensated for stability - eliminates BOM cost and layout risk of external COUT. |
| Stable with capacitive loads | Operates reliably with any output capacitance - simplifies filtering and EMI suppression design. |
| Laser-trimmed bandgap core | 0.1% initial accuracy achieved via factory trimming - removes need for system-level calibration. |
| Low 50µVRMS noise | Enables high-resolution data acquisition without post-filtering - improves SNR in 16+ bit ADC applications. |
Applications
| Portable Power Monitoring | Precision Sensor Biasing |
|---|---|
Use Scenario: Real-time battery voltage tracking in Bluetooth earbuds and smartwatches with 12-bit SAR ADCs. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 3.3V reference for ADC VREF input. Use Value: Enables ±0.1% battery SOC estimation accuracy across –10°C to +60°C operating range without recalibration. |
Use Scenario: Biasing resistive bridge sensors (e.g., strain gauges, pressure transducers) in handheld test equipment. IC Role / Device Role / Timing Role: Precision 3.3V excitation source for ratiometric measurement circuits. Use Value: Eliminates gain error drift from supply variation - maintains <0.05% full-scale linearity over temperature. |
| Industrial Data Acquisition | Medical Instrumentation |
Use Scenario: Reference for isolated 16-bit sigma-delta ADCs in PLC analog input modules. IC Role / Device Role / Timing Role: Local shunt reference on isolated side, rejecting common-mode noise up to 2.5kV. Use Value: Delivers 50µVRMS noise floor and 25ppm/°C drift - meets IEC 61000-4-5 surge immunity requirements. |
Use Scenario: Reference for ECG front-end ADCs in portable patient monitors requiring FDA Class II compliance. IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference for biopotential signal digitization. Use Value: Supports ≥100dB SNR at 1kHz with <1µV p-p 0.15–150Hz noise - satisfies AAMI EC11 clinical accuracy thresholds. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431ACDBVR | 2.5V fixed output, ±0.5% initial accuracy, 100ppm/°C tempco, SOT23-3 package | Lower precision and higher drift - suitable only for non-critical 8–10-bit systems | Select when cost sensitivity outweighs accuracy needs and 3.3V output is not mandatory. |
| ADR3433ARJZ-R7 | 3.3V output, ±0.1% accuracy, 10ppm/°C tempco, but 5-pin SOT23 package and series topology | Requires external bypass cap and higher quiescent current; incompatible pinout and bias architecture | Choose for ultra-low-drift (<10ppm/°C) needs where board space allows larger package and series-reference complexity. |
Compared with TLVH431ACDBVR and ADR3433ARJZ-R7, MAX6138AEXR33 delivers tighter initial accuracy and lower package profile than the TLVH431, while offering simpler two-terminal biasing and better space efficiency than the ADR3433 - making it optimal for compact, high-accuracy shunt-reference implementations.
Availability
MAX6138AEXR33 is available at Aetrix Electronics and suitable for portable power monitoring, precision sensor biasing, industrial data acquisition, medical instrumentation, and battery management systems requiring stable component supply with guaranteed long-term availability.
Supply support for MAX6138AEXR33 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 demanding industrial, medical, and communications applications.
The MAX6138 family delivers high-accuracy, low-drift shunt voltage references in ultra-small SC70 packages - engineered specifically for space-constrained, battery-powered, and high-reliability measurement systems.
FAQ
What is the maximum shunt current rating for MAX6138AEXR33?
The MAX6138AEXR33 supports a continuous shunt current range of 60µA to 15mA. Absolute maximum reverse current is 20mA - exceeding this risks permanent damage. For reliable long-term operation, keep ISHUNT ≤15mA and ensure power dissipation stays within the 174mW SC70 derating limit at +70°C ambient.
Does MAX6138AEXR33 require an external output capacitor?
No, MAX6138AEXR33 does not require an external output capacitor for stability. It is internally compensated and remains stable with any output capacitance - including zero capacitance - eliminating BOM cost, layout constraints, and ESR-related instability risks common in series references.
What is the temperature coefficient specification for MAX6138AEXR33?
The MAX6138AEXR33 has a guaranteed maximum temperature coefficient of 25ppm/°C over –40°C to +85°C. Typical performance is ±4ppm/°C, and polarity may vary per unit - some devices exhibit positive drift, others negative - but all meet the 25ppm/°C limit across the full industrial temperature range.
How is the source resistor (RS) calculated for MAX6138AEXR33?
RS is sized using: [VS(MIN) – 3.3V] / [60µA + ILOAD(MAX)] > RS > [VS(MAX) – 3.3V] / [20mA + ILOAD(MIN)]. This ensures minimum 60µA shunt current under worst-case low-VS/high-load, and prevents exceeding 20mA under worst-case high-VS/low-load - protecting MAX6138AEXR33 while maintaining regulation.
Can Pin 3 of MAX6138AEXR33 be left unconnected?
Yes - Pin 3 of MAX6138AEXR33 is designated N.C. (No Connection) and must be left floating or connected to Pin 2 (cathode). It serves no internal function; connecting it elsewhere or applying voltage will compromise device operation or reliability.
MAX6138AEXR33 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- SC-70, SOT-323
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 15 mA
- Tolerance:
- ±0.1%
- Temperature Coefficient:
- 25ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 50µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 67 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-3
MAX6138AEXR33 FAQ
1.How can I place an order for MAX6138AEXR33 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6138AEXR33 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 MAX6138AEXR33 reliable?
The price and inventory of MAX6138AEXR33 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6138AEXR33 is usually 5 days.
3.What payment methods are accepted for MAX6138AEXR33?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6138AEXR33 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6138AEXR33?
MAX6138AEXR33 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6138AEXR33 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 MAX6138AEXR33?
For technical support, including MAX6138AEXR33 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6138AEXR33 requirements.
6.How does Aetrix verify that MAX6138AEXR33 is sourced from the original manufacturer or authorized distributors?
All MAX6138AEXR33 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 MAX6138AEXR33 meets industry standards.
7.What is the process for return or replacement of MAX6138AEXR33?
All MAX6138AEXR33 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6138AEXR33, 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 MAX6138AEXR33 part is unused and in its original packaging.
Return procedure for MAX6138AEXR33:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6138AEXR33 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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…
