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STMicroelectronics TS821BILT
- Part No.:
- TS821BILT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TS821BILT.pdf
- Description:
- IC VREF SHUNT 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,990
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Product details
Overview
TS821BILT from STMicroelectronics is a 1.225V, ±0.5% precision micropower shunt voltage reference in SOT23-3L package, operating from 45μA to 12mA with 120ppm/°C tempco and 0.25–0.5Ω static impedance, used for accurate biasing and feedback in battery-operated power supplies.
For engineers reviewing the TS821BILT datasheet, TS821BILT pinout, TS821BILT application, or TS821BILT equivalent, key selection criteria include initial accuracy at 0.5%, ultra-low quiescent current, stability under capacitive loads, and industrial temperature range support (-40°C to +85°C).
Technical Context
The TS821BILT functions as a two-terminal shunt reference, sinking cathode current to maintain a stable 1.225V across its terminals. Its operation requires an external series resistor to set the cathode current between 45μA (min) and 12mA (max), with output voltage tightly regulated over temperature and load variations.
It delivers high DC precision (±0.5% at 25°C, ±6mV over -40°C to +85°C), low wideband noise (200nV/√Hz, 10Hz–10kHz), and minimal dynamic impedance (0.25–0.5Ω), enabling use in high-resolution ADC references and low-drift analog signal chains where supply headroom is constrained.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.225V nominal; ±0.5% tolerance at 25°C ensures ≤6.1mV absolute error in precision feedback loops. |
| Initial Accuracy | ±6mV over full -40°C to +85°C range supports stable regulation without calibration in industrial environments. |
| Operating Current | 45μA minimum enables operation in energy-harvesting or coin-cell systems where supply current is severely limited. |
| Tempco | 120ppm/°C max guarantees ≤0.1% output drift over 125°C span-critical for unregulated input conditions. |
| Static Impedance | 0.25–0.5Ω ensures <0.5mV output shift per 1mA load change, preserving accuracy in varying sink-current applications. |
| Noise Density | 200nV/√Hz (10Hz–10kHz) minimizes added noise in high-gain sensor front-ends and precision DAC buffers. |
Pinout & Package
SOT23-3L plastic micropackage (3-pin surface-mount) with 1.9mm × 2.8mm footprint and 0.95mm pitch; RoHS-compliant, ECOPACK® certified, rated for 260°C soldering (10s).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Reference ground return path | Connected to system GND; completes shunt current loop and defines 0V reference node. |
| Cathode (Pin 2) | Output voltage terminal | Provides stable 1.225V; sinks all operating current; must be decoupled locally for noise immunity. |
| No Connect (Pin 3) | Unused internal terminal | Internally unconnected; left floating per datasheet-no external tie required or recommended. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low operating current | 45μA max at 25°C enables direct use with high-value bias resistors in low-power battery systems. |
| Capacitive-load stability | Stable with up to 100µF output capacitance-eliminates need for isolation resistors in SMPS feedback networks. |
| Low dynamic impedance | 0.25–0.5Ω maintains voltage accuracy despite rapid current transients in pulsed-sensing circuits. |
| Long-term stability | 120ppm drift after 1000 hours supports >10-year calibration intervals in instrumentation-grade equipment. |
Applications
| Battery Charger Feedback | Portable Medical Sensor Bias |
|---|---|
Use Scenario: Precision voltage reference for CC/CV loop control in Li-ion charger ICs with variable input voltage. IC Role / Device Role / Timing Role: Shunt reference providing stable 1.225V feedback to error amplifier, replacing higher-current bandgap references. Use Value: Enables <50μA quiescent design while maintaining ±0.5% output regulation across temperature and aging. | Use Scenario: Reference for 16-bit ADC in handheld ECG monitor powered by single CR2032 cell. IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference for ADC VREF input, directly biased from 3.3V rail via series resistor. Use Value: Delivers 200nV/√Hz noise floor and <0.1% total error-meeting EN ISO 14155 clinical accuracy requirements. |
| Industrial SMPS Monitoring | Wireless IoT Node Power Supervision |
Use Scenario: Secondary-side voltage sensing in isolated 24V-to-5V flyback converter for PLC I/O modules. IC Role / Device Role / Timing Role: Shunt reference in optocoupler feedback path, regulating output via TL431-compatible interface. Use Value: Stable 120ppm/°C tempco and 0.5Ω impedance ensure consistent regulation across -40°C to +70°C ambient. | Use Scenario: Supply voltage monitoring and brown-out detection in BLE-enabled environmental sensor node. IC Role / Device Role / Timing Role: Reference for comparator-based VDD supervisor; activated only during periodic wake-up cycles. Use Value: 45μA min operating current allows microamp-level sleep current budgeting without sacrificing reset threshold accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BIDBZR | 2.5V fixed output; 100μA min operating current; 30ppm/°C tempco; SOT23-3 | Higher voltage output requires resistor divider for 1.225V use, increasing noise and error; better tempco but higher IQ | Select when system already uses 2.5V references and board space permits divider network. |
| MAX6008BEUR+T | 1.25V output; ±0.2% initial accuracy; 3μA typical IQ; SC70-3 package | Lower IQ and tighter accuracy, but 1.25V output differs by 25mV; SC70 footprint incompatible with SOT23-3 layout | Choose for ultra-low-power designs where 1.25V is acceptable and re-layout is feasible. |
Compared with TLVH431BIDBZR and MAX6008BEUR+T, the TS821BILT uniquely combines exact 1.225V output, SOT23-3 compatibility, and sub-50μA operation-making it optimal for retrofitting legacy 1.225V feedback circuits without redesign.
Availability
TS821BILT is available at Aetrix Electronics and suitable for battery chargers, portable medical sensors, industrial SMPS, and wireless IoT nodes requiring stable component supply with guaranteed long-term sourcing.
Supply support for TS821BILT 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.
The TS821 series belongs to ST's precision analog reference product line, engineered specifically for space-constrained, low-power applications demanding high initial accuracy and thermal stability without external compensation.
FAQ
What is the minimum cathode current required for TS821BILT to regulate within specification?
The TS821BILT requires a minimum cathode current of 45μA at 25°C and 50μA across the full -40°C to +85°C range to maintain ±0.5% output voltage accuracy. Below this threshold, regulation degrades rapidly-verified by Figure 1 and Table 5 in the official datasheet.
Can TS821BILT drive a 100µF capacitor directly without oscillation?
Yes-the TS821BILT is explicitly characterized for stability with up to 100µF output capacitance (see Figure 4 notes and "High stability when used with capacitive loads" feature). No series isolation resistor is needed, unlike many competing shunt references.
How does the 120ppm/°C temperature coefficient translate to actual voltage drift?
Over the -40°C to +85°C range (125°C span), the 120ppm/°C tempco results in maximum drift of 125 × 120ppm = 0.015 = 1.5% of 1.225V, or ±18.4mV. However, datasheet Table 5 limits total tolerance to ±6mV, meaning tempco is bounded by initial accuracy and curvature compensation.
Is Pin 3 (NC) required to be grounded or left floating?
Pin 3 is internally unconnected (No Connect) per Figure 7 and package description. It must be left floating-neither grounded nor tied to any potential-as confirmed by ST's mechanical drawing and electrical test configuration in the datasheet.
TS821BILT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.225V
- Voltage - Output (Max):
- -
- Current - Output:
- 12 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- 120ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 50 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TS821BILT FAQ
1.How can I place an order for TS821BILT through Aetrix?
Please submit a Request for Quotation (RFQ) for TS821BILT 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 TS821BILT reliable?
The price and inventory of TS821BILT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS821BILT is usually 5 days.
3.What payment methods are accepted for TS821BILT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS821BILT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS821BILT?
TS821BILT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS821BILT 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 TS821BILT?
For technical support, including TS821BILT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS821BILT requirements.
6.How does Aetrix verify that TS821BILT is sourced from the original manufacturer or authorized distributors?
All TS821BILT 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 TS821BILT meets industry standards.
7.What is the process for return or replacement of TS821BILT?
All TS821BILT units undergo pre-shipment inspection (PSI). If there is an issue with TS821BILT, 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 TS821BILT part is unused and in its original packaging.
Return procedure for TS821BILT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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