The LP38693SD-3.3 from Texas Instruments is a 500mA low-dropout CMOS linear regulator with 3.3V fixed output in a WSON-6 package. With 250mV dropout at 500mA and 55uA ground current, it provides efficient regulation for portable and automotive applications.<\/p>\n
| \u062c\u0647\u062f \u0627\u0644\u062e\u0631\u062c<\/td>\n | 3.3 V (fixed)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||
| \u062a\u064a\u0627\u0631 \u0627\u0644\u0625\u062e\u0631\u0627\u062c<\/td>\n | 500 mA<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||
| \u062c\u0647\u062f \u0627\u0644\u0625\u062f\u062e\u0627\u0644<\/td>\n | 2.7 V to 10 V<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||
| \u062c\u0647\u062f \u0627\u0644\u062a\u0633\u0631\u0628<\/td>\n | 250 mV (typ at 500mA, VOUT=5V)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||
| Ground Current<\/td>\n | 55 uA (typ at full load)<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||
| PSRRR<\/td>\n | 50 dB at 100kHz<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||
| \u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n | -40C to +125C<\/td>\n<\/tr>\n<\/table>\n\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n\u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\nProduct Overview The LP38693SD-3.3 from Texas Instruments is a 500mA low-dropout CMOS linear regulator with 3.3V fixed output in a WSON-6 package. With 250mV dropout at 500mA and 55uA ground current, it provides efficient regulation for portable and automotive applications. Key Specifications Output Voltage 3.3 V (fixed) Output Current 500 mA Input Voltage 2.7 V […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,29],"tags":[],"chip_brand":[138],"class_list":["post-7213","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-power-management-ics-pmic","chip_brand-ti"],"acf":{"brief_explanation":"500mA LDO, 3.3V fixed, 10V max input, 250mV VDO, WSON-6, AEC-Q100, enable pin","date_code":"","package_case":"WSON-6 (3.00 x 3.00 x 0.90 mm, exposed pad)","in_stock":13646,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lp3869.pdf","price":"$0.74 @ 1ku","product_introduction":"The LP38693SD-3.3 from Texas Instruments is a 500mA low-dropout CMOS linear regulator with a fixed 3.3V output in a WSON-6 package with exposed thermal pad. The device accepts input voltages from 2.7V to 10V, providing flexible supply options from single-cell Li-Ion to 9V battery systems. The PMOS pass transistor provides 250mV typical dropout voltage at 500mA load (for 5V output variant), ensuring efficient regulation with minimal headroom. The CMOS design maintains ground pin current below 100uA regardless of load current, input voltage, or operating temperature, significantly improving efficiency compared to bipolar LDOs at light loads. The 50dB PSRR at 100kHz rejects input power supply noise, making the device suitable for post-regulation of switching converters. The enable pin allows power sequencing and reduces quiescent current to 1uA when disabled. The WSON-6 package with exposed thermal pad provides low thermal resistance (51C\/W), enabling full 500mA output even in high ambient temperatures. AEC-Q100 Grade 1 qualification (WSON options) supports automotive applications.","working_principle":"The LP38693SD-3.3 uses a PMOS pass transistor for low-dropout regulation. (1) PMOS Pass Element: Unlike NPN or NMOS regulators that require VOUT + VBE or VOUT + VGS headroom, the PMOS pass transistor requires only a small VDS for regulation, enabling the 250mV dropout voltage. The gate of the PMOS is driven by the error amplifier to regulate output voltage. (2) Error Amplifier: A precision trimmed bandgap reference provides a stable reference voltage. The error amplifier compares a divided version of the output voltage to the reference and adjusts the PMOS gate drive to maintain regulation. The 2% output accuracy at 25C reflects the bandgap trimming precision. (3) Ground Current: The PMOS gate is voltage-driven, requiring negligible DC gate current. The 55uA ground current consists of the bandgap reference, error amplifier, and bias circuit supply current, independent of load. (4) Foldback Current Limit: Under overload conditions, the current limit circuit reduces the output current as the output voltage decreases (foldback), limiting power dissipation. (5) Thermal Shutdown: When the junction temperature exceeds approximately 165C, the thermal shutdown circuit turns off the pass transistor, protecting the device from damage.","pin_description":"
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