FDA803D - 1A, 35V Ultra-Low Noise LDO | Texas Instruments
MPN: FDA803D β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.85 | $4.85 |
| 10 | $4.36 | $43.60 |
| 100 | $3.88 | $388.00 |
| 500 | $3.49 | $1,745.00 |
| 1,000 | $3.1 | $3,100.00 |
Drop-in alternatives for FDA803D β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
TPS7A4700RGWR
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TPS7A4701RGWR-Q1
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TPS7A4701RGWT
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FDA803D Maximum Ratings & Electrical Characteristics
| Output Type | Adjustable |
| Output Voltage Range | 1.4 V to 34 V |
| Maximum Output Current | 1 A |
| Input Voltage Range | 3 V to 35 V |
| Dropout Voltage | 200 mV at 1 A |
| Output Noise | 4.17 uVrms (20 Hz to 100 kHz) |
| PSRR | 72 dB at 1 kHz |
| Quiescent Current | 6.4 mA |
| Thermal Resistance | 31.4 C/W |
| Operating Temperature | -40C to +125C |
| Package | VQFN-20 (RGW) 5x5 mm |
| Mounting Type | Surface Mount |
| MSL Level | 2 (1 year) |
| RoHS Status | Compliant |
| Enable Pin | Yes (active-high) |
FDA803D Pin Configuration
| Pin 1 | OUT β Regulated output voltage |
| Pin 5 | GND β Ground |
| Pin 6 | EN β Enable (active high) |
| Pin 7 | IN β Input supply |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
FDA803D is suitable for 6 applications: High-End Audio DAC Power Supply, RF Transceiver Power Rail, Precision ADC Reference Buffer, Industrial 24V Bus Power, Test and Measurement Instrumentation, Portable Medical Devices.
High-End Audio DAC Power Supply
The FDA803D provides a clean 5V rail for audio DACs with 4.17uVrms noise. In a typical audio DAC application, the FDA803D is placed between the system 5V rail and the DAC's AVDD pin, with a 10uF ceramic capacitor on input and output. The ultra-low noise ensures that the DAC's dynamic range is not compromised by power supply noise. Compared to switching regulators, the LDO eliminates switching noise but dissipates more power; for a 12V-to-5V conversion at 500mA, power dissipation is 3.5W. The high PSRR (72 dB at 1 kHz) further attenuates any residual ripple from upstream converters, making it ideal for high-end audio systems where signal integrity is paramount.
Recommended
RF Transceiver Power Rail
The FDA803D is ideal for powering PLLs and VCOs in RF transceivers. Its 4.17uVrms noise and 72 dB PSRR at 1 kHz ensure that the phase noise of the PLL is not degraded by power supply noise. In a typical RF application, the FDA803D is used to generate a clean 3.3V rail from a 5V supply, with a 10uF output capacitor to maintain stability. The low dropout voltage (200 mV at 1A) allows efficient operation even with tight input-output headroom. The enable pin can be used to sequence power-up in multi-rail RF systems, preventing latch-up or incorrect initialization. The wide input range (up to 35V) also supports direct connection to battery voltages in portable RF devices.
Recommended
Precision ADC Reference Buffer
The FDA803D can be used to buffer the reference voltage for precision ADCs, providing a low-noise, stable supply. In a data acquisition system, the FDA803D is placed between the reference IC and the ADC's VREF pin, with a 10uF capacitor to filter noise. The 4.17uVrms noise ensures that the ADC's SNR is not limited by the reference supply. The high PSRR (72 dB at 1 kHz) rejects any noise from the digital supply, which is critical in mixed-signal systems. The enable pin allows the reference to be powered down during standby, reducing power consumption. The wide output voltage range (1.4V to 34V) makes it suitable for various ADC reference voltages.
Recommended
Industrial 24V Bus Power
The FDA803D can regulate a 24V industrial bus down to a clean 5V or 3.3V rail for sensors and microcontrollers. Its input voltage range of up to 35V provides ample headroom for 24V systems with transients. In a typical industrial application, the FDA803D is used with a 10uF input capacitor to handle voltage spikes and a 10uF output capacitor for stability. The low dropout voltage (200 mV at 1A) ensures efficient operation even when the input voltage drops during brownout conditions. The thermal shutdown protection prevents damage from overload, making it reliable in harsh industrial environments. The enable pin can be used for remote on/off control in distributed control systems.
Recommended
Test and Measurement Instrumentation
The FDA803D is used in test and measurement equipment to provide clean, stable power rails for precision analog circuits. Its ultra-low noise (4.17uVrms) and high PSRR (72 dB at 1 kHz) are essential for maintaining measurement accuracy. In a typical instrument, the FDA803D is used to power the analog front-end, with a 10uF output capacitor to filter noise. The wide output voltage range (1.4V to 34V) allows it to generate various supply voltages needed by different stages. The enable pin can be used to sequence power-up in complex instruments, preventing damage from incorrect power-on order. The thermal shutdown protection ensures safe operation in benchtop environments.
Recommended
Portable Medical Devices
The FDA803D is suitable for portable medical devices that require low-noise power supplies for sensitive analog circuits. Its low quiescent current (6.4 mA) helps extend battery life, while the ultra-low noise (4.17uVrms) ensures accurate readings from sensors. In a typical medical device, the FDA803D is used to power an ECG amplifier or glucose sensor, with a 10uF output capacitor for stability. The wide input range (3V to 35V) allows it to operate from various battery configurations. The enable pin can be used to power down unused sections to save power. The small VQFN-20 package is ideal for space-constrained designs.
Recommended
Recommended Products Summary
Engineering reference data for FDA803D β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TPS7A4700RGWR | TPS7A4701RGWR-Q1 | TPS7A3301RGWR |
|---|---|---|---|---|
| Package | VQFN-20 (RGW) | VQFN-20 (RGW) - same | VQFN-20 (RGW) - same | VQFN-20 (RGW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Output Current | 1 A | 1 A | 1 A | 1 A (negative) |
| Output Voltage Range | 1.4V to 34V | 1.4V to 34V | 1.4V to 34V | -36V to -1.4V |
| Enable Pin | Yes (active-high) | No | Yes (active-high) | Yes (active-high) |
| Automotive Grade | No | No | Yes (AEC-Q100) | No |
| Output Noise | 4.17 uVrms | 4.17 uVrms | 4.17 uVrms | 4.17 uVrms |
| PSRR at 1 kHz | 72 dB | 72 dB | 72 dB | 72 dB |
Key Differentiators
- Only VQFN-20 family member with enable pin (vs TPS7A4700RGWR)
- Automotive grade option available (vs TPS7A4701RGWR-Q1)
- Positive voltage polarity (vs TPS7A3301RGWR)
Design Notes
At VIN=12V, VOUT=5V, and 1A load, power dissipation is 7W. The VQFN-20 package has theta_JA of 31.4 C/W, resulting in a 220C junction temperature rise. A heatsink or at least 1 square inch of copper pour is required for reliable operation above 2W dissipation.
Place input and output capacitors as close to the IC pins as possible. Use a 10uF ceramic capacitor on the input and a 10uF ceramic capacitor on the output. Add a 0.1uF ceramic capacitor in parallel for high-frequency noise bypass.
Do not exceed the maximum input voltage of 35V. Ensure the external resistor divider uses 1% or better tolerance resistors to maintain output voltage accuracy. The NR/SS capacitor controls startup time and noise bandwidth - do not omit it.
Compliance Information
RoHS compliant per TI product page. Not AEC-Q100 qualified - choose TPS7A4701RGWR-Q1 for automotive.
