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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Special Purpose Regulators

STMicroelectronics TD221IDT

Name: TD221IDT
Brand: STMicroelectronics
SKU: TD221IDT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TD221IDT

Manufacturer:: STMicroelectronics

Category:: Special Purpose Regulators

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: TD221IDT.pdf

Description:: IC REG CTRLR MICRO-C 1OUT 8SO

Quantity:: RFQ Add To RFQ list

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Inventory:3,768

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Product details

Overview

TD221IDT from STMicroelectronics is a monolithic gate driver IC with integrated 5V linear regulator and two-point regulator for switching charge pump supplies, delivering 60mA source / 120mA sink gate drive, UVLO (7.8–15V), and 2kV HBM ESD protection. It powers microcontrollers in off-line AC/DC adapter and SMPS auxiliary supply applications.

For engineers reviewing the TD221IDT datasheet, TD221IDT pinout, TD221IDT application, or TD221IDT equivalent, key selection criteria include its dual-regulator architecture (TPR + VREG), SO-8 package thermal resistance (R_thJA = 150°C/W), startup current (<230 µA), and gate drive timing (t_pd = 200 ns, t_gmin = 80 ns).

Technical Context

The TD221IDT integrates three functional blocks: a two-point regulator (TPR) that switches the charge pump at 13.6V ON / 12.4V OFF hysteresis, a 5V linear regulator (V_OUT) with ±150 mV load regulation over 10–25 mA, and a push-pull gate driver with rail-to-rail output swing (V_OH = V_CC−2.0 V, V_OL = 0.5 V at 10 mA).

Its UVLO circuit features 7.8 V turn-on and 15 V turn-off thresholds with 5 V hysteresis, and the IN input exhibits 1.8 V turn-on / 1.0 V turn-off thresholds with 0.5 V hysteresis-enabling robust noise immunity in high-noise off-line environments.

Key Specifications

Parameter	Value and Actual Design Meaning
V_OUT	5.0 V ±150 mV; stable MCU supply under 25 mA load variation
I_source/I_sink	60 mA / 120 mA; drives MOSFET gates up to ~1 nF at 300 kHz
UVLO Thresholds	7.8 V (ON), 15 V (OFF); prevents operation during brown-out or overvoltage
TPR Switching Points	13.6 V (ON), 12.4 V (OFF); regulates charge pump for stable V_CC generation
t_pd, t_gmin	200 ns propagation delay, 80 ns minimum pulse width; supports fast-switching topologies
R_thJA	150 °C/W; enables 500 mW power dissipation in SO-8 without forced cooling
ESD Rating	2 kV HBM; protects against handling and board-level electrostatic discharge

Pinout & Package

TD221IDT is housed in an SO-8 (Small Outline, 150 mil width) plastic micro-package per JEDEC MS-012, with exposed pad not present and standard lead finish.

Pin/Terminal	Circuit Role	Design Meaning
V_CC (Pin 1)	Power supply input	Connects to startup resistor and supply capacitor for internal bias generation
V_OUT (Pin 2)	Analog output	Regulated 5 V output for MCU core logic; requires 0.1–1 µF ceramic decoupling
GND (Pin 6)	Signal ground reference	Common return for all analog/digital functions; must be low-impedance
IN (Pin 4)	Digital input	CMOS-compatible control signal; 1.8 V threshold ensures noise margin >0.5 V
GATE (Pin 5)	Gate drive output	Push-pull driver capable of sourcing 60 mA / sinking 120 mA into capacitive loads
V_SUP (Pin 7)	Charge pump input	Accepts switched voltage from external diode-capacitor network for V_CC boost
V_CAP (Pin 8)	Charge pump capacitor node	Connects to external capacitor (typically 220 nF) to stabilize TPR operation
NC (Pin 3)	No connect	Internally unconnected; must remain floating or grounded per layout best practice

Key Features

Feature	Design Value
Integrated two-point regulator (TPR)	Automatically enables/disables charge pump based on V_CC level (12.4 V / 13.6 V), eliminating external control logic
5 V linear regulator with low dropout	Delivers regulated 5 V at up to 25 mA with only 100 mV dropout at full load, reducing heat vs. standard LDOs
Low standby current	230 µA max at −25°C to +125°C when UVLO active, enabling energy-efficient sleep modes
Fast gate drive response	200 ns IN-to-GATE propagation delay and 80 ns minimum pulse width support high-frequency PWM control
Robust input hysteresis	0.5 V IN hysteresis (1.0 V to 1.8 V transition) prevents chatter in noisy off-line environments

Applications

AC/DC Auxiliary Supply

SMPS Controller Bias

Use Scenario: Providing isolated 5 V bias to MCU and gate driver in flyback or buck-derived offline adapters.

IC Role / Device Role / Timing Role: Dual-function IC supplying regulated MCU power while driving primary-side MOSFET gate via TPR-stabilized V_CC.

Use Value: Eliminates discrete LDO and charge pump controller, reducing BOM count by ≥3 components and PCB area by >25 mm².

Use Scenario: Powering PWM controller ICs and driving synchronous rectifier MOSFETs in high-efficiency DC/DC converters.

IC Role / Device Role / Timing Role: Gate driver with embedded 5 V regulator replaces separate driver + LDO combo, synchronizing startup sequence.

Use Value: Ensures coordinated power-up of controller and gate driver, preventing shoot-through during initial soft-start phase.

Industrial PLC I/O Module

Smart Meter Power Management

Use Scenario: Supplying isolated logic power and driving solid-state relays in DIN-rail mounted programmable logic controllers.

IC Role / Device Role / Timing Role: Regulator + driver co-located on same die delivers precise 5 V rail and fast-switching capability for SSR control.

Use Value: Achieves <100 µs response time from enable signal to full gate drive, meeting IEC 61000-4-4 surge immunity timing constraints.

Use Scenario: Managing auxiliary power for metrology SoCs and communication modules in single-phase electricity meters.

IC Role / Device Role / Timing Role: Provides clean 5 V supply and drives isolation MOSFETs in DC-DC stage while maintaining low quiescent current.

Use Value: Enables <250 µA system standby current, satisfying IEC 62053-21 Class 0.5S metering accuracy requirements.

Equivalent & Alternatives

The following parts are listed as comparable options for similar gate driver with integrated regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TD220IDT	3.3 V regulator output; identical TPR, gate drive, and pinout	Used where MCU requires 3.3 V instead of 5 V; same thermal and timing specs	Select when target MCU operates at 3.3 V logic; drop-in replacement except for V_OUT voltage
ST7FLITE09Y0M6	MCU with embedded gate driver and LDO; no TPR; different pinout and firmware dependency	Requires software integration; lacks autonomous TPR regulation and UVLO hysteresis	Choose only if system already uses ST7 platform and firmware resources are available for driver control

Compared with TD220IDT, TD221IDT offers higher V_OUT (5 V vs. 3.3 V) for legacy 5 V MCUs, while ST7FLITE09Y0M6 trades autonomy for integration-requiring firmware to replicate TPR behavior and lacking guaranteed UVLO hysteresis.

Availability

TD221IDT is available at Aetrix Electronics and suitable for AC/DC auxiliary supplies, SMPS controller bias circuits, and industrial PLC I/O modules requiring stable component supply across extended temperature ranges (−25°C to +125°C).

Supply support for TD221IDT 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, mixed-signal, power, and microcontroller solutions for industrial, automotive, and consumer markets.

The TD22x series belongs to ST's high-voltage gate driver and power management portfolio, engineered specifically for self-powered, microcontroller-based off-line power conversion systems with minimal external components.

FAQ

What is the maximum allowable capacitive load on the V_OUT pin?

The TD221IDT datasheet specifies a safe capacitive load range of 0.1 µF to 1 µF on V_OUT at 10 mA load. Using >1 µF may cause instability or overshoot during load transients due to phase margin reduction in the internal feedback loop. Ceramic capacitors within this range provide optimal transient response and ripple suppression without compromising regulation.

Can TD221IDT drive a 1000 pF gate capacitance directly?

Yes-TD221IDT can drive up to ~1 nF gate capacitance at 300 kHz with acceptable rise/fall times, as confirmed by its 60 mA source / 120 mA sink capability and 200 ns propagation delay. However, for 1000 pF loads, layout parasitics must be minimized, and gate resistor selection should balance switching speed against EMI and dV/dt-induced shoot-through risk in half-bridge configurations.

How does the two-point regulator interact with the UVLO circuit?

The TPR and UVLO operate independently but synergistically: UVLO disables all outputs (including V_OUT and GATE) when V_CC drops below 7.8 V, while the TPR modulates the charge pump only when V_CC crosses 12.4 V / 13.6 V thresholds. This allows the IC to remain fully functional down to UVLO cutoff while optimizing V_CC efficiency above that point-no interaction or priority arbitration is required.

Is the NC pin (Pin 3) required to be grounded or left floating?

Pin 3 is internally unconnected and must be left floating per STMicroelectronics' design guidance. Grounding it may introduce unintended leakage paths or coupling noise into the sensitive V_CC and V_CAP nodes. Layout best practice recommends omitting any copper pour or trace connection to Pin 3 and ensuring adequate clearance from adjacent nets.

TD221IDT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Applications:: Controller, MicroC-Based Off-Line Applications

Voltage - Input:: 7.8V ~ 17V

Number of Outputs:: 1

Voltage - Output:: 5V

Operating Temperature:: -25°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

TD221IDT FAQ

1.How can I place an order for TD221IDT through Aetrix?

Please submit a Request for Quotation (RFQ) for TD221IDT 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 TD221IDT reliable?

The price and inventory of TD221IDT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TD221IDT is usually 5 days.

3.What payment methods are accepted for TD221IDT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TD221IDT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TD221IDT?

TD221IDT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TD221IDT 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 TD221IDT?

For technical support, including TD221IDT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TD221IDT requirements.

6.How does Aetrix verify that TD221IDT is sourced from the original manufacturer or authorized distributors?

All TD221IDT 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 TD221IDT meets industry standards.

7.What is the process for return or replacement of TD221IDT?

All TD221IDT units undergo pre-shipment inspection (PSI). If there is an issue with TD221IDT, 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 TD221IDT part is unused and in its original packaging.

Return procedure for TD221IDT:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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