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STMicroelectronics TSM101ACD
- Part No.:
- TSM101ACD
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TSM101ACD.pdf
- Description:
- IC VREF SERIES 1% 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,987
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Product details
Overview
TSM101ACD from STMicroelectronics is a precision voltage and current controller IC for secondary-side feedback in isolated switching power supplies, integrating a 1.24V ±1% bandgap reference, two ORed op-amps (1MHz GBW), and an enableable 1.4mA current source. It operates from 4.5V to 32V supply, delivers up to 10mA reference output, and is used in battery chargers with dual-stage constant-voltage/constant-current regulation.
For engineers reviewing the TSM101ACD datasheet, TSM101ACD pinout, TSM101ACD application, or TSM101ACD equivalent, this device serves as a drop-in upgrade to TL431-based designs requiring tighter current limit accuracy, integrated dual-loop control, and optocoupler-driven PWM feedback coordination in compact SO8 packaging.
Technical Context
The TSM101ACD implements a dual-loop analog control architecture: one op-amp compares scaled output voltage against the 1.24V reference (pin 1), while the second compares sense resistor voltage (pin 5) against a derived reference (pin 3); their outputs are ORed internally to drive the common output (pin 6). The 1.4mA current source (enabled by grounding pin 2) injects offset into the current-sense path to dynamically adjust charge current thresholds.
Its 1MHz gain-bandwidth product ensures stable loop response in typical flyback SMPS operating below 500kHz, and the 4.5–32V supply range supports wide-input industrial and automotive auxiliary rails. The SO8 package enables surface-mount integration without compromising thermal performance (θJA = 130–200°C/W).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Voltage Reference | 1.24V ±1% (TSM101A grade), enabling 1.5% end-of-charge voltage accuracy in NiCd/NiMH battery chargers |
| Reference Output Current | 10mA max, sufficient to bias R6/R7 divider networks and maintain stability under load |
| Op-Amp Gain-Bandwidth | 1MHz, supporting closed-loop bandwidth up to ~100kHz for fast transient response in CV/CC transitions |
| Current Source | 1.4mA ±15%, used to offset current-sense voltage by up to 140mV across 100Ω (R4), enabling dual-current profiles |
| Supply Voltage Range | 4.5V to 32V DC, compatible with auxiliary windings in universal-input 90–264VAC SMPS |
| Temperature Stability | ≤100 ppm/°C (voltage ref), ensuring <±15mV drift over –20°C to +80°C operating range |
| Input Offset Voltage | ±7mV max, limiting CV regulation error to <0.6% at 1.24V reference point |
Pinout & Package
Package: SO8 (Plastic Micropackage), 5.0mm × 6.2mm body, 1.27mm pitch, gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Vref) | Voltage Reference Output | 1.24V ±1% source, drives R6/R7 divider; must not be shorted - no internal short-circuit protection |
| 2 (Csen) | Current Source Enable Input | Logic-low (<0.6V) activates 1.4mA sink; open or >2V disables it - enables dual-charge-current modes |
| 3 (Crref) | Current Limit Reference Input | Connects to R2/R3 divider node; sets threshold voltage for current-loop op-amp comparison |
| 4 (GND) | Analog Ground Reference | Common return for reference, op-amps, and sense inputs; must tie to power ground at single point |
| 5 (Crin) | Current Sense Input | Receives voltage from sense resistor (R5); compared against Crref to trigger current-limit action |
| 6 (OUTPUT) | ORed Loop Output | Drives optocoupler LED anode directly; sinks up to 15mA to reduce primary-side PWM duty cycle |
| 7 (Vrin) | Voltage Regulation Input | Connects to R6/R7 divider midpoint; compared against Vref to regulate output voltage |
| 8 (Vcc) | Power Supply Input | 4.5–32V DC input; powers all internal blocks; bypass capacitor (C4) required between pin 8 and pin 4 |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent control loops | Separate voltage-regulation (Vrin/Vref) and current-limit (Crin/Crref) paths with internal OR logic on output |
| Enableable precision current source | 1.4mA sink activated by Csen pin; offsets current-sense voltage to implement programmable charge profiles |
| High-accuracy voltage reference | 1.24V ±1% initial tolerance (TSM101A), reducing need for external trimming in battery charger end-of-charge setpoints |
| Wide supply voltage operation | 4.5–32V range supports direct connection to auxiliary windings in universal-input SMPS without LDO pre-regulation |
| SO8 and DIP8 packaging options | PIN-to-PIN compatible footprints allow design reuse across through-hole and SMT production lines |
Applications
| NiCd/NiMH Battery Charger | Isolated Flyback SMPS |
|---|---|
|
Use Scenario: Charging 12V NiCd packs with 700mA nominal / 200mA maintenance current. IC Role / Device Role / Timing Role: Secondary-side voltage/current controller providing optocoupler feedback to primary PWM IC. Use Value: Enables precise dual-stage CV/CC regulation without discrete op-amps or external references, reducing BOM count by ≥4 components. |
Use Scenario: Regulating 15V/1A output in 90–264VAC universal-input flyback converter. IC Role / Device Role / Timing Role: Closed-loop feedback controller coordinating voltage stability and overcurrent foldback. Use Value: Maintains ±1.5% output voltage accuracy across line/load/temperature while supporting fast OCP response (<10µs). |
| Voltage Supervisor with Current Foldback | Multi-Cell Li-ion Charger Reference |
|
Use Scenario: Monitoring 5V rail in industrial PLC I/O module with automatic shutdown on overcurrent. IC Role / Device Role / Timing Role: Dual-threshold comparator using internal reference and ORed output to assert fault signal. Use Value: Eliminates need for separate voltage supervisor and current limiter ICs, saving PCB area and interconnect complexity. |
Use Scenario: Providing accurate 1.24V reference and current-sense interface for 3-cell Li-ion charging circuitry. IC Role / Device Role / Timing Role: Precision reference generator and current-loop amplifier for linear charger IC biasing. Use Value: Achieves ≤0.5% total voltage regulation error over temperature, meeting JEITA-compliant charge termination specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage and current controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACD | Single 2.5V shunt reference only; no op-amps, no current source, no OR logic | Requires external op-amps and discrete current sensing for dual-loop control | Select when only voltage regulation is needed and cost is primary constraint |
| UC384X series + TL431 | Primary-side PWM controller + external shunt reference; no integrated secondary-side current sensing | Relies on primary-side current sense; less accurate for output current limiting due to transformer leakage | Select for high-volume AC/DC adapters where primary-side control simplifies transformer design |
Compared with TL431ACD and UC384X-based solutions, TSM101ACD integrates dual-loop control, reference, and current-source offset in one SO8 IC-reducing component count by 6+ parts, improving current-limit accuracy by 3×, and enabling seamless dual-charge-mode battery management without redesigning feedback topology.
Availability
TSM101ACD is available at Aetrix Electronics and suitable for battery chargers, isolated flyback SMPS, voltage supervisors with current foldback, and multi-cell Li-ion charger reference circuits requiring stable component supply and long-term manufacturability.
Supply support for TSM101ACD 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, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.
The TSM101 series belongs to ST's Power Management Analog portfolio, engineered specifically for secondary-side feedback control in cost-sensitive, space-constrained isolated power converters requiring high integration and precision.
FAQ
What is the maximum output current capability of the TSM101ACD's voltage reference?
The TSM101ACD voltage reference (pin 1) delivers up to 10mA continuously, verified per datasheet Section 3 electrical characteristics. This current supports standard resistor-divider networks (e.g., 1kΩ/12kΩ) while maintaining 1.24V accuracy within ±1%. Exceeding 10mA risks reference voltage droop and thermal instability, as the device lacks internal short-circuit protection.
How does the current source on pin 2 affect the current regulation threshold?
Grounding pin 2 enables the internal 1.4mA current source, which flows through external resistor R4 to generate an offset voltage (Voffset = 1.4mA × R4) added to the sense resistor voltage. This raises the effective current threshold - for example, with R4 = 100Ω, Voffset = 140mV reduces regulated charge current from 700mA to 200mA in a 12V NiCd charger, as confirmed in Application Note AN896.
Can TSM101ACD operate with a 3.3V supply rail?
No - the absolute minimum supply voltage is 4.5V per Absolute Maximum Ratings (Section 2). At 3.3V, internal bandgap reference startup fails, op-amp biasing collapses, and output stage cannot drive optocoupler LEDs. For low-voltage applications, use an auxiliary winding or LDO to boost Vcc to ≥4.5V, as detailed in Section 5.2 of the datasheet.
What is the purpose of the ORed output architecture between the two op-amps?
The ORed output forces the lowest voltage of the two op-amp outputs to dominate pin 6, ensuring that either overvoltage or overcurrent conditions independently trigger feedback to reduce PWM duty cycle. This fail-safe behavior prevents simultaneous CV and CC conflicts and guarantees immediate response to whichever fault occurs first - critical for battery safety and SMPS reliability.
TSM101ACD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Active
- Reference Type:
- Series
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- -
- Current - Output:
- 10 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- 4.5V ~ 32V
- Current - Supply:
- 2mA
- Current - Cathode:
- -
- Operating Temperature:
- -20°C ~ 80°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TSM101ACD FAQ
1.How can I place an order for TSM101ACD through Aetrix?
Please submit a Request for Quotation (RFQ) for TSM101ACD 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 TSM101ACD reliable?
The price and inventory of TSM101ACD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TSM101ACD is usually 5 days.
3.What payment methods are accepted for TSM101ACD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TSM101ACD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TSM101ACD?
TSM101ACD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TSM101ACD 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 TSM101ACD?
For technical support, including TSM101ACD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TSM101ACD requirements.
6.How does Aetrix verify that TSM101ACD is sourced from the original manufacturer or authorized distributors?
All TSM101ACD 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 TSM101ACD meets industry standards.
7.What is the process for return or replacement of TSM101ACD?
All TSM101ACD units undergo pre-shipment inspection (PSI). If there is an issue with TSM101ACD, 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 TSM101ACD part is unused and in its original packaging.
Return procedure for TSM101ACD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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