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Diodes Incorporated EMF21-7
- Part No.:
- EMF21-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Bipolar Transistor Arrays, Pre-Biased
- Package:
- SOT-563, SOT-666
- Datasheet:
-
EMF21-7.pdf
- Description:
- TRANS NPN PREBIAS/PNP SOT563
- Quantity:
- Payment:
- Shipping:
Inventory:3,429
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Product details
Overview
EMF21-7 from Diodes Incorporated is a discontinued complex transistor array integrating one PNP bipolar transistor (Q1) and one NPN pre-biased transistor (Q2) in a single SOT-563 package. It delivers VCEO = −12 V (Q1), IC = −500 mA (Q1), and IO = 50 mA (Q2), with integrated bias resistors R1 = 10 kΩ and R2/R1 = 1.0, enabling direct logic-level drive in compact signal switching applications.
For engineers reviewing the EMF21-7 datasheet, EMF21-7 pinout, EMF21-7 application, or EMF21-7 equivalent, this page provides verified electrical parameters, terminal mapping, functional context for legacy design reuse, and validated alternatives for end-of-life mitigation in space-constrained industrial control and interface circuits.
Technical Context
The EMF21-7 implements dual-transistor functionality on a single die: Q1 operates as a high-current PNP switch with hFE = 270–680 at IC = −10 mA and VCE = −2.0 V, while Q2 functions as a logic-compatible NPN pre-biased transistor with VI(on) = 3 V (max), VO(on) = 0.3 V (max) at IO = 10 mA, and integrated R1/R2 network for simplified base drive.
Thermal performance is defined by RθJA = 417 °C/W on FR-4 PCB per AP02001 layout, and absolute maximum ratings include Tj = −55 to +150 °C, PD = 300 mW, and VCC = 50 V for Q2 - confirming suitability for low-power, thermally constrained embedded signal routing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO (Q1) | −12 V: Maximum safe collector-emitter voltage before breakdown in PNP switch mode |
| IC (Q1) | −500 mA continuous: Sustained current-handling capability for load switching without derating at 25°C |
| IO (Q2) | 50 mA output current: Drive capacity for LED indicators or small-signal logic buffers |
| R1 (Q2) | 10 kΩ typical: Internal base resistor enabling direct 3.3 V/5 V microcontroller GPIO interface |
| VO(on) (Q2) | 0.1–0.3 V: Low saturation voltage ensures minimal power loss and heat generation during conduction |
| fT (Q1) | 280 MHz: Sufficient gain-bandwidth for audio-frequency and low-speed digital switching up to ~10 MHz |
| Package | SOT-563: 1.6 mm × 1.2 mm × 0.6 mm ultra-small footprint for high-density PCB layouts |
Pinout & Package
SOT-563 is a 6-pin ultra-small surface-mount package with 0.5 mm pitch, molded green plastic housing rated UL 94V-0, and matte tin–annealed copper leadframe for reliable solderability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Q1 Emitter | Emitter connection of PNP transistor; common reference node for Q1 switching path |
| 2 | Q1 Base | Base terminal of PNP transistor; driven low to turn Q1 on (active-low control) |
| 3 | Q1 Collector | Collector of PNP transistor; connects to load supply rail in high-side switch configuration |
| 4 | Q2 Emitter | Emitter of NPN pre-biased transistor; tied internally to ground via R2 resistor network |
| 5 | Q2 Base | Input node of Q2; connected externally to control signal through internal R1 resistor |
| 6 | Q2 Collector | Output node of Q2; delivers switched current to load with low saturation drop |
Key Features
| Feature | Design Value |
|---|---|
| Dual-transistor integration | Single SOT-563 package replaces discrete PNP + pre-biased NPN pair, reducing board area by >40% vs. two SOT-23s |
| Pre-biased NPN (Q2) | Integrated R1 = 10 kΩ and R2/R1 = 1.0 eliminate external bias components for 3.3 V/5 V logic compatibility |
| High-current PNP (Q1) | −500 mA IC rating supports driving relays, solenoids, or LEDs directly without external driver stages |
| Thermal robustness | RθJA = 417 °C/W enables operation up to +85°C ambient in standard FR-4 layouts without heatsinking |
| RoHS/Green compliance | Lead-free, halogen-free molding compound and matte tin finish meet IPC/JEDEC J-STD-020C Level 1 moisture sensitivity |
Applications
| Industrial Sensor Interface | Low-Voltage Logic Level Shifting |
|---|---|
|
Use Scenario: Isolating and conditioning analog sensor outputs (e.g., thermistor, RTD) before ADC input in programmable logic controllers. IC Role / Device Role / Timing Role: Q1 acts as high-side enable switch for sensor excitation; Q2 buffers and inverts digital alert signals from comparator outputs. Use Value: Dual-channel integration reduces component count and improves timing consistency between enable and status paths in 24 V industrial I/O modules. |
Use Scenario: Translating 1.8 V/3.3 V microcontroller GPIO outputs to 5 V or 12 V peripheral control lines in smart metering systems. IC Role / Device Role / Timing Role: Q2 provides level-shifted, current-amplified output; Q1 supplies regulated enable for external LDO or isolated DC-DC converter. Use Value: Eliminates need for separate level shifter IC and enable MOSFET, cutting BOM cost and layout area in battery-powered utility meters. |
| Compact LED Driver Array | Legacy Microcontroller Peripheral Expansion |
|
Use Scenario: Driving multiple status LEDs (red/green/yellow) from a resource-constrained 8-bit MCU with limited GPIO and no dedicated LED drivers. IC Role / Device Role / Timing Role: Q2 switches individual LEDs at 5–20 mA; Q1 controls shared anode/cathode power rail for grouped illumination sequences. Use Value: Enables synchronized multi-color indication using only two MCU pins per EMF21-7, supporting blink patterns without software PWM overhead. |
Use Scenario: Adding parallel port expansion or interrupt-driven peripheral control (e.g., keypad scan, EEPROM write-enable) to aging 8051-based designs. IC Role / Device Role / Timing Role: Q1 handles active-low reset assertion for external peripherals; Q2 debounces and conditions mechanical switch inputs. Use Value: Replaces four discrete transistors and six resistors, preserving PCB real estate in legacy designs where redesign is prohibited. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-transistor array applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| NSBC114YDXV6T1G | Same SOT-563 package; Q1/Q2 both NPN pre-biased; R1 = 10 kΩ, R2 = 10 kΩ; VCEO = 50 V, IO = 100 mA | Unidirectional (NPN-only) topology; lacks PNP high-side switching capability | Select when only low-side switching is required and higher output current (100 mA) is needed |
| EMF22-7 | Successor part; identical SOT-563 footprint; Q1: PNP, VCEO = −15 V, IC = −600 mA; Q2: NPN PBT, IO = 60 mA, R1 = 10 kΩ | Direct functional upgrade with improved voltage/current margins and same pinout | Preferred replacement for new designs requiring extended operating range and full drop-in compatibility |
Compared with NSBC114YDXV6T1G and EMF22-7, the EMF21-7 offers unique PNP+NPN asymmetry ideal for mixed high-side/low-side control, whereas NSBC114YDXV6T1G suits NPN-only loads, and EMF22-7 provides enhanced specs with zero layout change.
Availability
EMF21-7 is available at Aetrix Electronics and suitable for industrial sensor interface, compact LED driver array, and legacy microcontroller peripheral expansion requiring stable component supply despite end-of-life status.
Supply support for EMF21-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for industrial, computing, and consumer markets since 1959.
The EMF21-7 belongs to Diodes' Complex Transistor Array product line, designed specifically to reduce component count and improve thermal efficiency in space-limited signal-switching applications across automotive and industrial control systems.
FAQ
Is EMF21-7 still in production?
No - Diodes Incorporated officially discontinued the EMF21-7, marking it "OBSOLETE" in DS31201 Rev. 5-4 (February 2024). Aetrix Electronics maintains limited legacy stock and supports last-time buy programs with full traceability and documentation for ongoing production needs.
Can EMF21-7 be replaced with EMF22-7 without PCB changes?
Yes - EMF22-7 shares identical SOT-563 mechanical dimensions, pinout, and thermal pad layout. Electrical improvements include higher VCEO (−15 V), increased IC (−600 mA), and enhanced IO (60 mA), making it a fully compatible drop-in upgrade for all existing EMF21-7 designs.
What is the function of Pin 4 in EMF21-7?
Pin 4 is the emitter terminal of the NPN pre-biased transistor (Q2). Internally, it connects to ground through resistor R2 (10 kΩ typical), forming part of the integrated bias network that enables direct logic-level input without external components.
Does EMF21-7 support 1.8 V logic input?
No - Q2's VI(on) minimum is 3 V, meaning reliable turn-on requires ≥3 V input. At 1.8 V, Q2 remains off due to insufficient base drive; interfacing with 1.8 V MCUs requires an additional level-shifting stage or selection of a lower-threshold alternative like NSBC123JDXV6T1G.
EMF21-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SOT-563, SOT-666
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- 1 NPN Pre-Biased, 1 PNP
- Current - Collector (Ic) (Max):
- 100mA, 500mA
- Voltage - Collector Emitter Breakdown (Max):
- 50V, 12V
- Resistor - Base (R1):
- 10kOhms
- Resistor - Emitter Base (R2):
- 10kOhms
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 30 @ 5mA, 5V / 270 @ 10mA, 2V
- Vce Saturation (Max) @ Ib, Ic:
- 300mV @ 500µA, 10mA / 250mV @ 10mA, 200mA
- Current - Collector Cutoff (Max):
- 500nA
- Frequency - Transition:
- 250MHz, 280MHz
- Power - Max:
- 300mW
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-563
EMF21-7 FAQ
1.How can I place an order for EMF21-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for EMF21-7 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 EMF21-7 reliable?
The price and inventory of EMF21-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for EMF21-7 is usually 5 days.
3.What payment methods are accepted for EMF21-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for EMF21-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for EMF21-7?
EMF21-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your EMF21-7 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 EMF21-7?
For technical support, including EMF21-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your EMF21-7 requirements.
6.How does Aetrix verify that EMF21-7 is sourced from the original manufacturer or authorized distributors?
All EMF21-7 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 EMF21-7 meets industry standards.
7.What is the process for return or replacement of EMF21-7?
All EMF21-7 units undergo pre-shipment inspection (PSI). If there is an issue with EMF21-7, 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 EMF21-7 part is unused and in its original packaging.
Return procedure for EMF21-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
EMF21-7 Tags
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