STMicroelectronics LDK120C08R

Overview

LDK120C08R from STMicroelectronics is a 200 mA, 0.8 V fixed-output low-dropout linear regulator with 100 mV typical dropout at 100 mA, 100 µA max quiescent current, ±2.0% output voltage tolerance at 25 °C, and operation from 1.9 V to 5.5 V input. It delivers ultra-low noise (51 µV_RMS, 10 Hz–100 kHz with 10 nF bypass) and logic-controlled shutdown (<1 µA OFF mode), targeting power rails in portable battery-powered systems.

For engineers reviewing the LDK120C08R datasheet, LDK120C08R pinout, LDK120C08R application, or LDK120C08R equivalent, key selection criteria include its 0.8 V fixed output, SOT323-5L package compatibility with 1 µF ceramic output capacitors, thermal shutdown at 160 °C, and enable-controlled low-power state for mobile and imaging subsystems.

Technical Context

The LDK120C08R employs a PMOS pass transistor architecture enabling ultra-low dropout and minimal quiescent current across temperature. Its internal bandgap reference and error amplifier maintain tight output regulation under load transients up to 200 mA while supporting stable operation with 1 µF ceramic C_OUT and optional 10 nF bypass capacitor on the BYP pin.

Logic-level enable control (V_EN < 0.4 V for shutdown, > 1.2 V for active) interfaces directly with microcontroller GPIOs. Integrated short-circuit current limiting (400 mA typ.) and thermal protection (160 °C trip with 20 °C hysteresis) ensure robust fault handling without external components.

Key Specifications

Pinout & Package

LDK120C08R is packaged in SOT323-5L (1.8 × 2.0 mm, 0.95 mm pitch), a space-constrained surface-mount package suitable for high-density portable PCBs. Pin functions are validated per STMicroelectronics DS9378 Rev 9 (Table 1, p.4).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, low-I_Q LDO applications.

Compared with XC6210B082MR-G, LDK120C08R provides 33% higher current and integrated thermal protection; versus RT9013-12GB, it delivers the exact 0.8 V output required without compromising dropout or noise performance.

Availability

LDK120C08R is available at Aetrix Electronics and suitable for mobile phone baseband power, digital still camera sensor bias, wearable health monitor MCU core, and industrial IoT edge node PMU requiring stable component supply across automotive, medical, and consumer production programs.

Supply support for LDK120C08R 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 microcontrollers, power management ICs, sensors, and analog devices for industrial, automotive, and consumer markets.

The LDK120 series belongs to ST's high-performance LDO portfolio, engineered specifically for ultra-low-noise, ultra-low-quiescent-current regulation in space-constrained, battery-sensitive applications such as portable imaging and wearables.

FAQ

What is the minimum input voltage required for LDK120C08R to regulate 0.8 V output?

The minimum input voltage is determined by dropout: at 100 mA load, typical dropout is 100 mV, so VIN(min) = 0.8 V + 0.1 V = 0.9 V. However, the absolute minimum specified operating VIN is 1.9 V per datasheet Table 2 - operation below 1.9 V is not guaranteed and may cause instability or loss of regulation.

Can LDK120C08R be used with a 2.2 µF ceramic output capacitor instead of 1 µF?

Yes. The datasheet specifies stability with C_OUT from 1 µF to 22 µF (Table 4, footnote). A 2.2 µF X7R ceramic capacitor improves load-transient response and reduces output impedance at higher frequencies, provided its ESR remains below 1 Ω at 100 kHz per Figure 25 stability region.

Is the BYP pin mandatory for achieving 51 µV_RMS noise performance?

Yes. The 51 µV_RMS value (Table 4, eN) is measured with a 10 nF bypass capacitor on the BYP pin. Without it, noise rises to 148 µV_RMS (eN(2)). For applications demanding lowest noise - such as RF bias or precision ADC references - the BYP capacitor is essential and must be placed adjacent to the BYP and GND pins.

Does LDK120C08R support reverse polarity protection on the input?

No. The device lacks internal reverse-voltage protection. If reverse input voltage (e.g., due to incorrect battery insertion or hot-swap events) exceeding -0.3 V is possible, an external series Schottky diode or dedicated protection IC must be added - otherwise permanent damage may occur per Absolute Maximum Ratings (Table 2, V_IN = -0.3 V).