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STMicroelectronics TSM101CN
- Part No.:
- TSM101CN
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
TSM101CN.pdf
- Description:
- IC VREF SERIES 1.24V 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,319
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Product details
Overview
TSM101CN from STMicroelectronics is a dual-loop voltage and current controller IC for secondary-side feedback in isolated SMPS, integrating a 1.24V ±1% precision 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 targets battery chargers requiring simultaneous CV/CC regulation with optocoupler-driven PWM control.
For engineers reviewing the TSM101CN datasheet, TSM101CN pinout, TSM101CN application, or TSM101CN equivalent, this device serves as a drop-in functional upgrade over TL431-based designs where precise dual-loop regulation, temperature-stable current limiting, and integrated offset capability are required.
Technical Context
The TSM101CN implements two independent control loops sharing a single 1.24V reference: one compares scaled output voltage (via R6/R7 divider) against Vref at Pin 1, the other compares sense-resistor voltage (at Pin 5) against a reference derived from Vref and R2/R3. Both op-amp outputs are internally ORed (diode-wired) to drive the common OUTPUT pin (Pin 6).
Its built-in current generator (Io = 1.4mA, ±500 ppm/°C tempco) connects to Pin 2 (Csen); sinking this pin below 0.6V enables the source to inject offset current into the current-sense path, allowing dynamic charge-current adjustment without external components. The IC supports DIP8 and SO8 packages and operates across –20°C to +80°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Voltage Reference | 1.24V ±1% (TSM101A grade), enabling ±15mV load regulation over 1–10mA - sufficient for 1.45V/cell NiCd end-of-charge accuracy |
| Op-Amp Gain Bandwidth | 1MHz - supports stable closed-loop response in typical flyback SMPS with <100kHz switching frequency |
| Supply Voltage Range | 4.5V to 32V - accommodates auxiliary winding voltages across universal-input AC/DC adapters |
| Current Source Output | 1.4mA ±10%, enabled by <0.6V on Pin 2 - offsets sense voltage by up to 140mV across 100Ω (R4), enabling dual-current modes (e.g., 700mA/200mA) |
| Input Offset Voltage | ±7mV max - ensures ≤0.5% error in 200mV current-sense threshold setting |
| Common-Mode Rejection | 80dB min - maintains regulation accuracy despite ground noise between sense resistor and IC GND (Pin 4) |
| Thermal Resistance | 130–200°C/W (DIP8) - allows 200mW dissipation at ≤80°C ambient without heatsink |
Pinout & Package
Package: DIP8 (Plastic Dual In-line Package), 0.3" wide, through-hole mount. Compatible with standard DIP sockets and wave-soldering processes.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Vref) | Voltage Reference Output | 1.24V ±1% source, drives R2/R3 divider and R6/R7 divider; must not be shorted - no internal short-circuit protection |
| 2 (Csen) | Current Source Enable Input | Logic-low (<0.6V) enables 1.4mA sink; open or pulled high disables - used to select charge-current mode via external switch or comparator |
| 3 (Crref) | Current Limit Reference Input | Connects to R2/R3 node; sets current-limit threshold by scaling Vref - determines trip point for Crin (Pin 5) |
| 4 (GND) | Analog Ground Reference | Common return for all internal circuits; must tie to low-impedance power ground near sense resistor to minimize CM error |
| 5 (Crin) | Current Sense Input | Inverting input of current-loop op-amp; compares sense-resistor voltage against Crref - direct connection to shunt resistor terminal |
| 6 (OUTPUT) | ORed Loop Output | Open-collector output driving optocoupler LED; sinks up to 15mA - interfaces directly with PC817/HLK-1009 without external transistor |
| 7 (Vrin) | Voltage Regulation Input | Inverting input of voltage-loop op-amp; connects to R6/R7 divider midpoint - senses scaled output voltage for CV regulation |
| 8 (Vcc) | Power Supply Input | 4.5–32V DC input; powers all internal blocks; requires ≥10µF local bypass (C4) due to high PSRR sensitivity |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent control loops | Single-chip replacement for discrete TL431 + comparator + offset circuit - reduces BOM count by ≥4 components and PCB area by >30% |
| Enableable precision current source | 1.4mA source with 0.6V enable threshold - eliminates need for external DAC or MOSFET switch to modify current limit dynamically |
| ORed op-amp outputs | Internal diode-wired outputs ensure tighter regulation: voltage loop dominates during CV phase; current loop takes over during CC phase without conflict |
| High-PSRR voltage reference | 90dB supply rejection - maintains 1.24V stability despite ripple on 12–24V auxiliary winding, critical for low-noise battery charging |
| Wide operating temperature range | –20°C to +80°C industrial grade - validated for sealed NiCd/NiMH charger enclosures with passive cooling |
Applications
| Battery Charger (NiCd/NiMH) | Voltage Supervisor |
|---|---|
|
Use Scenario: 12V/700mA switched-mode battery charger with automatic transition from constant-current to constant-voltage mode and dual-rate charging (700mA normal / 200mA maintenance). IC Role / Device Role / Timing Role: Secondary-side voltage/current controller providing optocoupler feedback to primary-side PWM IC (e.g., UC3842), using internal 1.24V reference and ORed op-amps to enforce both limits simultaneously. Use Value: Eliminates need for separate current-sense comparator and reference; enables precise 1.45V/cell end-of-charge cutoff with <±1% total error across temperature. |
Use Scenario: Overvoltage protection circuit for 5V/12V/24V DC rails in industrial PLC I/O modules, triggering shutdown when rail exceeds 5% tolerance. IC Role / Device Role / Timing Role: Precision voltage monitor comparing rail voltage against internal 1.24V reference via resistor divider; OUTPUT pin drives latch or MOSFET gate upon violation. Use Value: Achieves ±1% trip accuracy without external reference; 80dB CMRR rejects ground bounce from adjacent digital circuits. |
| SMPS Current Limiter | Optocoupler Feedback Driver |
|
Use Scenario: Secondary-side current limiting for 48V telecom rectifier, protecting against short-circuit while maintaining voltage regulation under load transients. IC Role / Device Role / Timing Role: Current-loop amplifier comparing sense-resistor voltage to Vref-derived threshold; overrides voltage loop when current exceeds setpoint. Use Value: Provides fast, accurate current limiting (≤10µs response) with 1.4mA offset capability to adjust trip point without changing sense resistor. |
Use Scenario: Isolated feedback interface between secondary-side regulation circuit and primary-side PWM controller in medical-grade AC/DC adapter. IC Role / Device Role / Timing Role: Open-collector OUTPUT (Pin 6) directly drives PC817 LED anode; GND (Pin 4) referenced to secondary ground ensures galvanic isolation integrity. Use Value: Delivers 15mA sink current at 2.5V saturation - sufficient to fully saturate optocoupler LED across full CTR range (50–600%), ensuring robust PWM control. |
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 |
|---|---|---|---|
| TL431 + LM393 | Discrete solution: TL431 provides 2.5V ref (±0.5%), LM393 adds current-comparator function; requires ≥6 external passives | Lacks integrated current source and OR logic - cannot implement seamless CV/CC transition or programmable offset without additional transistors | Choose only if legacy design reuse or cost sensitivity outweighs board space and calibration effort |
| UC384X + opto | Primary-side controller with current-mode PWM; no secondary-side sensing - relies on transformer turns ratio and primary current sense | No direct output voltage/current measurement - regulation accuracy degrades with line/load/cross-regulation effects | Select when system-level cost optimization favors primary-side integration over secondary-side precision |
Compared with TL431+LM393, TSM101CN reduces component count and improves CV/CC coordination; versus UC384X, it delivers superior output regulation accuracy and simplifies compliance with battery charging safety standards via direct secondary monitoring.
Availability
TSM101CN is available at Aetrix Electronics and suitable for battery chargers, industrial power supplies, voltage supervisors, and isolated feedback systems requiring stable component supply with guaranteed long-term continuity.
Supply support for TSM101CN 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 automotive, industrial, and consumer markets.
The TSM101 series belongs to ST's Power Management Analog portfolio, engineered specifically for secondary-side regulation in isolated DC-DC converters - emphasizing integration, precision, and reliability in cost-sensitive power applications.
FAQ
What is the maximum allowable output current from the Vref pin (Pin 1)?
The Vref pin delivers up to 10mA continuously, as specified in the absolute maximum ratings and confirmed in electrical characteristics (Iout = 10mA typ.). Exceeding this draws excessive current from the internal bandgap core, causing thermal drift and potential damage. For divider networks drawing >5mA, add a 100nF ceramic capacitor directly at Pin 1 to stabilize reference impedance.
Can TSM101CN operate with a 3.3V supply?
No - the minimum supply voltage is 4.5V per the operating conditions table. At 3.3V, internal biasing fails: the op-amps lose gain, the reference collapses below 1.2V, and the current source ceases operation. For low-voltage applications, use an auxiliary winding or LDO to generate ≥4.5V for Vcc (Pin 8) independently of the main output rail.
How does the ORed output architecture prevent control loop conflict?
The two op-amp outputs connect via internal diodes to a shared open-collector OUTPUT pin (Pin 6). Whichever op-amp pulls lower dominates the feedback signal - e.g., during overload, the current-loop op-amp forces OUTPUT low before the voltage loop can react, ensuring current limit takes precedence without external logic or priority circuitry.
Is the current source compatible with lithium-ion battery charging profiles?
Yes - the 1.4mA current source enables precise current tapering by offsetting the sense voltage, supporting CC/CV transitions and constant-current maintenance phases. However, full Li-ion safety (e.g., temperature cutoff, termination voltage accuracy <±5mV) requires external thermistor monitoring and fine-tuning of R2/R3 and R4 values per cell chemistry.
TSM101CN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Reference Type:
- Series
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- -
- Current - Output:
- 10 mA
- Tolerance:
- -
- 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:
- Through Hole
- Supplier Device Package:
- 8-DIP
TSM101CN FAQ
1.How can I place an order for TSM101CN through Aetrix?
Please submit a Request for Quotation (RFQ) for TSM101CN 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 TSM101CN reliable?
The price and inventory of TSM101CN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TSM101CN is usually 5 days.
3.What payment methods are accepted for TSM101CN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TSM101CN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TSM101CN?
TSM101CN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TSM101CN 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 TSM101CN?
For technical support, including TSM101CN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TSM101CN requirements.
6.How does Aetrix verify that TSM101CN is sourced from the original manufacturer or authorized distributors?
All TSM101CN 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 TSM101CN meets industry standards.
7.What is the process for return or replacement of TSM101CN?
All TSM101CN units undergo pre-shipment inspection (PSI). If there is an issue with TSM101CN, 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 TSM101CN part is unused and in its original packaging.
Return procedure for TSM101CN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TSM101CN Tags
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AZ431LBNTR-G1
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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