Counterfeit and defect prevention
Visual and packaging inspection
Electrical performance verification
Service Email:
[email protected]
>
PQ09RD21
Sharp Microelectronics
IC REG LINEAR 9V 2A TO220-4
58127 Pcs New Original In Stock
Linear Voltage Regulator IC Positive Fixed 1 Output 2A TO-220-4
Request Quote
(Ships tomorrow)
*Quantity
Minimum 1
Minimum 1
5.0 / 5.0
- (462 Ratings)
PQ09RD21
Product Overview
7923736
DiGi Electronics Part Number
PQ09RD21-DGManufacturer
Sharp Microelectronics
PQ09RD21
Description
IC REG LINEAR 9V 2A TO220-4Inventory
58127 Pcs New Original In Stock
Linear Voltage Regulator IC Positive Fixed 1 Output 2A TO-220-4
Quantity
Minimum 1
Minimum 1
Purchase and inquiry
Warranty & Returns
How to Order
Shipping & Delivery
Quality Assurance
365 - Day Quality Guarantee - Every part fully backed.
90 - Day Refund or Exchange - Defective parts? No hassle.
Limited Stock, Order Now - Get reliable parts without worry.
Global Shipping & Secure Packaging
Worldwide Delivery in 3-5 Business Days
100% ESD Anti-Static Packaging
Real-Time Tracking for Every Order
Secure & Flexible Payment
Credit Card, VISA, MasterCard, PayPal, Western Union, Telegraphic Transfer(T/T) and more
All payments encrypted for security
PQ09RD21 Technical Specifications
Category
Power Management (PMIC), Voltage Regulators - Linear, Low Drop Out (LDO) Regulators
Packaging
-
Series
-
Product Status
Obsolete
Output Configuration
Positive
Output Type
Fixed
Number of Regulators
1
Voltage - Input (Max)
20V
Voltage - Output (Min/Fixed)
9V
Voltage - Output (Max)
-
Voltage Dropout (Max)
0.5V @ 2A
Current - Output
2A
Current - Quiescent (Iq)
10 mA
PSRR
55dB (120Hz)
Control Features
Enable
Protection Features
Over Current, Over Temperature
Operating Temperature
-20°C ~ 80°C
Mounting Type
Through Hole
Package / Case
TO-220-4
Supplier Device Package
TO-220-4
Base Product Number
PQ09
Datasheet & Documents
HTML Datasheet
PQ09RD21-DG
Environmental & Export Classification
RoHS Status
RoHS non-compliant
Moisture Sensitivity Level (MSL)
1 (Unlimited)
ECCN
EAR99
HTSUS
8542.39.0001
Additional Information
Other Names
425-1623-5
Standard Package
50
Reviews
5.0/5.0-(Show up to 5 Ratings)
December 02, 2025
포장이 튼튼해서 제품이 손상 없이 잘 도착했어요.
December 02, 2025
The support team’s expertise makes a real difference when I encounter challenges.
December 02, 2025
I trust DiGi Electronics to provide dependable and cost-effective solutions.
December 02, 2025
Clients commend their attention to detail in logistics, leading to zero delivery errors.
December 02, 2025
Every purchase from DiGi Electronics arrives faster than anticipated, saving me time.
December 02, 2025
The speed of delivery was outstanding, and their customer support was clear and helpful.
Publish Evalution
Evalution Message
Please enter your review message.
Please post honest comments and do not post ilegal comments.
Frequently Asked Questions (FAQ)
Can the Sharp Microelectronics PQ09RD21 be safely used as a direct replacement for the LM7809 in a high-current 9V power supply design, and what are the key thermal and electrical trade-offs to consider?
While the PQ09RD21 and LM7809 both provide a fixed 9V output, the PQ09RD21 offers superior performance with a lower dropout voltage (0.5V max at 2A vs. ~2V for the LM7809) and higher output current capability (2A vs. 1A). However, because the PQ09RD21 is obsolete and RoHS non-compliant, long-term sourcing and compliance may be issues. Thermally, the PQ09RD21’s lower dropout reduces power dissipation significantly—e.g., at 12V input and 2A load, it dissipates only 6W compared to ~12W for the LM7809—allowing smaller heatsinks. Ensure your PCB layout supports the TO-220-4 pinout and that enable functionality is properly managed if used. Always verify availability and consider a modern alternative like the MC7809ABD2TG for new designs.
What are the risks of using the obsolete PQ09RD21 in a new industrial design, and how can I mitigate potential supply chain and reliability concerns?
Using the PQ09RD21 in a new design introduces significant supply chain risk due to its obsolete status, despite current stock availability. Long-term production runs may face sudden part shortages or price spikes. Additionally, being RoHS non-compliant limits use in regulated markets like the EU. To mitigate, qualify a second-source modern equivalent such as the STMicroelectronics L7809CV or ON Semiconductor MC7809ABD2TG early in development. Perform drop-in testing to confirm compatibility in voltage regulation, thermal behavior, and enable functionality. Maintain a last-time buy strategy if committed, and document a clear migration path to avoid redesign delays later.
How does the enable pin on the PQ09RD21 affect system power management, and what circuit considerations are needed to avoid unintended shutdown or inrush current issues?
The PQ09RD21 includes an enable pin that allows dynamic control of the output, enabling power sequencing and low-power modes. However, improper handling can lead to partial activation or latch-up. The enable threshold is not fully specified in public datasheets, so empirical testing is recommended. Use a pull-down resistor (e.g., 10kΩ) to ensure the regulator stays off during power-up until the control signal is stable. When driving the enable pin from a microcontroller, include a series resistor (100–470Ω) to limit current and reduce noise coupling. Avoid floating the pin, as it may cause erratic behavior. Also, consider output capacitor discharge time when disabling, as residual voltage can affect downstream circuits.
What input voltage range and filtering components are required to ensure stable operation of the PQ09RD21 in a noisy automotive environment with load dump transients?
The PQ09RD21 accepts up to 20V input, but in automotive applications, load dump transients can exceed 40V. Therefore, you must include input protection such as a TVS diode (e.g., SMAJ33A) and a bulk capacitor (≥100µF low-ESR electrolytic) close to the input pin to absorb energy and limit voltage spikes. Additionally, a 10µF ceramic capacitor should be placed near the input for high-frequency noise suppression. Ensure the total input voltage never exceeds 20V under normal or transient conditions after clamping. The PSRR of 55dB at 120Hz helps reject ripple, but high-frequency noise from alternators or motors may require additional LC filtering. Always derate the input voltage by at least 20% for reliability.
Can the PQ09RD21 be paralleled with another linear regulator to increase output current beyond 2A, and what are the critical design challenges in doing so?
Paralleling the PQ09RD21 with another identical unit to exceed 2A output is not recommended without active current sharing. Even minor variations in output voltage (due to manufacturing tolerance or thermal gradients) can cause one regulator to carry most of the load, leading to thermal runaway. If paralleling is unavoidable, use ballast resistors (e.g., 0.1Ω, 2W) in series with each output to force current sharing, but this increases dropout voltage and power loss. A better approach is to replace the PQ09RD21 with a higher-current regulator like the LM338 (5A) or use a switching pre-regulator to reduce the input-output differential and minimize heat. Always monitor junction temperature and ensure adequate heatsinking if attempting parallel operation.
Quality Assurance (QC)
DiGi ensures the quality and authenticity of every electronic component through professional inspections and batch sampling, guaranteeing reliable sourcing, stable performance, and compliance with technical specifications, helping customers reduce supply chain risks and confidently use components in production.
PQ09RD21 CAD Models
Sharp Microelectronics PQ09RD21 PCB symbols & footprints
productDetail
