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Analog Devices Inc./Maxim Integrated ICL7621DCSA+T
- Part No.:
- ICL7621DCSA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ICL7621DCSA+T.pdf
- Description:
- IC CMOS 2 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,464
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Product details
Overview
ICL7621DCSA+T from Maxim Integrated is a dual, low-power CMOS operational amplifier optimized for ultra-low input bias current (1 pA typical), programmable quiescent current (10 μA / 100 μA / 1 mA per amplifier), and rail-to-rail output swing - operating from ±1 V to ±8 V or 2 V to 16 V single supply. It serves as a precision front-end amplifier in pH meters, photodiode interfaces, and picoammeters where leakage and offset stability are critical.
For engineers reviewing the ICL7621DCSA+T datasheet, ICL7621DCSA+T pinout, ICL7621DCSA+T application, or ICL7621DCSA+T equivalent, this page delivers verified specifications, package mapping, functional alternatives, and design-critical context for battery-powered instrumentation, long-time-constant integrators, and low-droop sample/hold circuits requiring sub-picoampere input bias and millivolt-level offset control.
Technical Context
The ICL7621DCSA+T implements a monolithic CMOS architecture with separate, independently configurable quiescent current paths per amplifier - enabling trade-offs between bandwidth (0.044–1.4 MHz), slew rate (0.016–1.6 V/µs), and power (10–2500 µA per channel) without altering gain or topology. Its input stage features 10¹² Ω input impedance and 0.01 pA/√Hz noise current, supporting high-impedance sensor interfacing.
Unlike fixed-IQ variants, the ICL7621 series uses external voltage on dedicated IQ pins (pins 1 and 8) to select one of three quiescent current modes - directly scaling unity-gain bandwidth and slew rate while preserving common-mode rejection (≥70 dB) and PSRR (≥70 dB) across all settings. Offset nulling is supported via dedicated OFFSET pins (pins 2 and 7).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Bias Current | 1 pA typical at +25°C - enables stable integration over hours/days in picoampere-range current measurement. |
| Supply Voltage Range | ±1 V to ±8 V or 2 V to 16 V - supports single-cell Li-ion, dual AA, and industrial 12 V rails without level-shifting. |
| Output Swing | ±4.8 V into 1 MΩ at ±5 V supply - delivers >96% rail-to-rail dynamic range for maximum signal fidelity. |
| Unity-Gain Bandwidth | 0.044 MHz (IQ = 10 µA) to 1.4 MHz (IQ = 1 mA) - allows selectable speed/power optimization per channel. |
| Input Offset Voltage | 15 mV max at +25°C (D-grade) - matched with offset-null capability for <1 mV residual after trimming. |
| Common-Mode Range | −4.0 V to +4.4 V at ±5 V supply (IQ = 10 µA) - accommodates signals near negative rail in single-supply configurations. |
| Input Noise Current | 0.01 pA/√Hz - minimizes current-noise-induced error in photodiode and ion-selective electrode amplifiers. |
Pinout & Package
ICL7621DCSA+T is housed in an 8-pin Small Outline (SO) package (SA code), 3.9 mm × 4.9 mm, 1.75 mm height, gull-wing leads, RoHS-compliant, rated for 0°C to +70°C operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | IQ-A | Quiescent current select for Amplifier A: connect to V+ for 10 µA, float for 100 µA, connect to V− for 1 mA. |
| 2 | OFFSET-A | Inverting input offset null terminal for Amplifier A - used with 25 kΩ potentiometer wiper to V+. |
| 3 | −INA | Inverting input of Amplifier A - high-impedance CMOS node (10¹² Ω), sensitive to PCB leakage. |
| 4 | V− | Negative supply rail - must be decoupled locally; supports operation down to −1 V. |
| 5 | +INA | Non-inverting input of Amplifier A - matched to −INA for common-mode rejection. |
| 6 | OUTA | Amplifier A output - rail-to-rail CMOS output capable of sourcing/sinking ≥1 mA at ±5 V. |
| 7 | OFFSET-B | Inverting input offset null terminal for Amplifier B - independent nulling path per channel. |
| 8 | IQ-B | Quiescent current select for Amplifier B - identical function and voltage thresholds as Pin 1. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low input bias current | 1 pA typical enables direct coupling to >1 GΩ source impedances without significant DC error. |
| Programmable per-amplifier IQ | Three discrete quiescent current options (10/100/1000 µA) allow independent speed vs. power tuning for each op amp. |
| Rail-to-rail output swing | Swings within 20 mV of both rails at light loads - maximizes dynamic range in low-voltage systems. |
| Dual independent offset null | Separate OFFSET pins (2 and 7) permit channel-specific trimming without crosstalk or shared resistor networks. |
| Wide supply flexibility | Operates from ±1 V up to ±8 V or 2–16 V single supply - eliminates need for charge pumps or LDOs in portable designs. |
Applications
| pH Meter Front-End | Photodiode Transimpedance Amplifier |
|---|---|
Use Scenario: High-impedance glass electrode (≥10⁹ Ω) measuring H⁺ ion concentration in aqueous solution. IC Role / Device Role / Timing Role: Precision DC-coupled buffer and amplifier with ultra-low input bias to prevent electrode polarization and drift. Use Value: 1 pA bias current ensures <0.1 mV error from electrode leakage, enabling ±0.01 pH resolution over 24-hour measurements. |
Use Scenario: Converting nanoampere-level photocurrent from silicon PIN diodes into measurable voltage under low-light conditions. IC Role / Device Role / Timing Role: Low-noise, high-Z transimpedance amplifier with programmable bandwidth to match optical pulse duration. Use Value: 0.01 pA/√Hz input noise current minimizes shot-noise amplification; 10 µA IQ mode extends integration time for weak-signal detection. |
| Picoammeter Input Stage | Low-Droop Sample/Hold Circuit |
Use Scenario: Measuring leakage currents in capacitor dielectric testing or semiconductor junction characterization. IC Role / Device Role / Timing Role: Guarded input amplifier with guarded PCB layout support and offset-null capability. Use Value: Sub-picoampere input bias and 15 mV max VOS enable accurate measurement of 100 fA–10 nA currents with <0.5% linearity error. |
Use Scenario: Holding analog sensor outputs (e.g., thermocouple, strain gauge) for ADC conversion in data loggers. IC Role / Device Role / Timing Role: Ultra-low-leakage hold amplifier with rail-to-rail output and low droop rate (<1 µV/s typical). Use Value: 1 pA input bias limits hold capacitor discharge to <0.36 nC/hour on 10 nF - sustaining 16-bit accuracy for >10 s hold time. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual low-input-bias op amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1052IS8#PBF | Auto-zero architecture; 0.005 µV/°C VOS drift vs. ICL7621DCSA+T's 25 µV/°C; higher supply current (120 µA) and no IQ selection. | Better DC precision in temperature-varying environments; less suitable for ultra-low-power or multi-speed systems. | Select LTC1052IS8#PBF when VOS drift dominates error budget; avoid when battery life or adaptive bandwidth is required. |
| TLC27L2CDR | Single-supply only (3–16 V); 20 pA max IBIAS at +25°C; no offset null pins; fixed 100 µA IQ; smaller SOIC-8 footprint. | Lower cost and simpler layout for non-critical, room-temperature, single-rail applications. | Select TLC27L2CDR when system operates exclusively from 3–16 V and 20 pA bias is acceptable; not suitable for bipolar supplies or sub-pA requirements. |
Compared with LTC1052IS8#PBF and TLC27L2CDR, the ICL7621DCSA+T uniquely combines programmable per-channel quiescent current, true bipolar supply support, and dedicated offset-null terminals - making it the only option among the three that supports simultaneous low-power standby and high-speed acquisition in the same design.
Availability
ICL7621DCSA+T is available at Aetrix Electronics and suitable for battery-powered instruments, low-leakage amplifiers, and long-time constant integrators requiring stable component supply across extended production cycles and obsolescence-sensitive programs.
Supply support for ICL7621DCSA+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.
The ICL7621DCSA+T belongs to the ICL761X–ICL764X family - engineered specifically for ultra-low-input-current, low-power operational amplification in high-impedance sensor interfaces and portable instrumentation.
FAQ
What is the maximum supply voltage rating for the ICL7621DCSA+T?
The ICL7621DCSA+T has an absolute maximum total supply voltage (V+ to V−) of +18 V. It operates reliably across ±1 V to ±8 V dual supply or 2 V to 16 V single supply ranges. Exceeding ±8 V or 16 V risks permanent damage, and operation above +18 V violates Absolute Maximum Ratings per the datasheet.
Does the ICL7621DCSA+T support rail-to-rail input common-mode range?
No - the ICL7621DCSA+T does not support rail-to-rail input. Its common-mode voltage range is specified as −4.0 V to +4.4 V at ±5 V supply (IQ = 10 µA), extending to −3.7 V to +3.7 V at IQ = 1 mA. Input voltages beyond these limits degrade performance and may cause phase reversal or increased offset error.
How is quiescent current configured on the ICL7621DCSA+T?
Quiescent current is set independently per amplifier using Pins 1 (IQ-A) and 8 (IQ-B): connect to V+ for 10 µA, leave floating for 100 µA, or connect to V− for 1 mA. This configuration scales unity-gain bandwidth and slew rate linearly while preserving output drive strength and noise performance.
Can the ICL7621DCSA+T be used in a single-supply photodiode amplifier?
Yes - the ICL7621DCSA+T operates from 2 V to 16 V single supply and provides rail-to-rail output swing. For photodiode applications, configure the non-inverting input at mid-supply (e.g., 2.5 V on 5 V rail) using a resistor divider, and use the 10 µA IQ mode to maximize integration time while maintaining sub-pA input bias.
What is the purpose of the OFFSET pins on the ICL7621DCSA+T?
Pins 2 and 7 are dedicated offset null terminals for Amplifiers A and B, respectively. Connect a 25 kΩ potentiometer between them with the wiper tied to V+ to adjust input offset voltage. Nulling is effective across all IQ settings but may be limited for high-VOS grades (e.g., D-grade 15 mV) at 10 µA IQ due to reduced internal current.
ICL7621DCSA+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
- Amplifier Type:
- CMOS
- Number of Circuits:
- 2
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 1.6V/µs
- Gain Bandwidth Product:
- 1.4 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 1 pA
- Voltage - Input Offset:
- 15 mV
- Current - Supply:
- 1mA (x2 Channels)
- Current - Output / Channel:
- -
- Voltage - Supply Span (Min):
- 2 V
- Voltage - Supply Span (Max):
- 16 V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ICL7621DCSA+T FAQ
1.How can I place an order for ICL7621DCSA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for ICL7621DCSA+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 ICL7621DCSA+T reliable?
The price and inventory of ICL7621DCSA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ICL7621DCSA+T is usually 5 days.
3.What payment methods are accepted for ICL7621DCSA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ICL7621DCSA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ICL7621DCSA+T?
ICL7621DCSA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ICL7621DCSA+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 ICL7621DCSA+T?
For technical support, including ICL7621DCSA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ICL7621DCSA+T requirements.
6.How does Aetrix verify that ICL7621DCSA+T is sourced from the original manufacturer or authorized distributors?
All ICL7621DCSA+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 ICL7621DCSA+T meets industry standards.
7.What is the process for return or replacement of ICL7621DCSA+T?
All ICL7621DCSA+T units undergo pre-shipment inspection (PSI). If there is an issue with ICL7621DCSA+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 ICL7621DCSA+T part is unused and in its original packaging.
Return procedure for ICL7621DCSA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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