[Introduction]A dry battery is a chemical battery that uses a paste electrolyte to generate direct current (a wet battery is a chemical battery that uses a liquid electrolyte). It is a primary battery, widely used in daily life and easy to carry. With the popularization of portable AV equipment and IT equipment, dry battery has become a very widely used mobile energy. Normally, the voltage of one dry battery is about 1.6V at the highest, and the discharge is terminated to the lowest 0.9V; the output voltage of two dry batteries in series is between 3.2V-1.8V. Most mobile devices need a certain constant voltage, generally 3V-5V, to ensure the normal operation of the system. Therefore, in a mobile device powered by one or two dry batteries, a booster chip that can meet the low-voltage operation of 0.9V is required to supply power to the system.
Shenzhen Yongfukang Technology Co., Ltd. is now vigorously promoting a low-power synchronous boost IC with 3uA ultra-low quiescent current and minimum start-up voltage of 0.65V for the application requirements of 1-2 dry batteries and lithium batteries for mobile devices. Its application advantages are as follows:
(1) To meet the application of low voltage such as a single cell and two dry batteries, the minimum operating voltage of most boost chips on the market is 2.5V-2.7V;
(2) TP8312 can output 5V/500mA in a single lithium battery, while the general charge pump boost output is 5V/200mA. Its low EMI characteristics avoid interference to FM radio and wireless microphones;
(3) TP8312 standby current is 3 microamps, suitable for applications requiring low power consumption and long standby time;
(4) Synchronous boost architecture with very few peripheral components.A small 10-differential Inductor can be used to achieve PCB area; typical application parameters
TP8312 is applied to single-cell dry battery 1.5V, dual-cell dry battery 3V, single-cell lithium battery 3.7V boost typical parameters are as follows:
A single dry cell 0.9V application is boosted to 3.3V/100mA.
Single-cell dry battery 1.5V application boost to 3.3V/190mA.
Double dry battery 1.8V application boost to 3.3V/230mA.
Double dry battery 3V application boost to 3.3V/550mA.
Single-cell lithium battery 2.8V application boost to 5V/380mA.
Single-cell lithium battery 3.6V application boost to 5V/600mA.
Single-cell dry battery/dual-cell dry battery/single-cell lithium battery application, boost output voltage/current and set resistance value corresponding to FB pin:
1. Product introduction
The TP8312 is a high efficiency, fixed frequency synchronous boost DC-DC converter. Low voltage technology allows the regulator to start up without high inrush current or output voltage overshoot from low voltage inputs. The 0.65V to 4.2V input voltage range makes the TP8312 suitable for single-cell, two-cell or three-cell alkaline, NiCd, NiMH, single-cell Li-Ion or Li-Polymer batteries. Current-mode operation provides good response to line and load changes, as well as switching inductor peak current limiting. Internal loop compensation and protection circuits reduce peripheral components. Anti-ringing circuitry reduces EMI caused by discontinuous mode operation. The output voltage is set by a small external resistor divider.
Input voltage working range: 0.65V—Vout
Adjustable output voltage range: 1.8V—5.5V, accuracy ±3%
High efficiency: up to 96%
1.0A Typical Peak Input Current Limit:
● IOUT>200mA@3.3VVOUT, 1.2VVIN
● IOUT>400mA@3.3VVOUT, 2.4VVIN
● IOUT>500mA@5.0VVOUT, 3.3VVIN
Output quiescent current: typ. 3uA Shutdown current:
Low input startup voltage: 0.85V, 1mA load Low input operating voltage: 0.65V
Feedback voltage: 1.23V
Automatic PFM/PWM switching working mode: -PWM working frequency: 400KHz -PFM output ripple: typical value 150mV
Inrush current limit and internal soft-start
Over temperature protection
Built-in synchronous rectification
3. Application products
One, Two, Three Alkaline Batteries and NiMH/NiCd Portable Products • Solar Cell Applications • Wireless Sensors • TWS Bluetooth Headsets • Smartphones, MP3 Players, Digital Cameras • Remote Controllers, Portable Devices • +3V to 5.0V Distributed power supply
4. TP8312 pin map
Five, TP8312 pin description
6. Schematic diagram and application description of TP8312 DEMO board
Seven, TP8312 DEMO board PCB design
Eight, TP8312 DEMO board patch picture
Nine, TP8312 DEMO board bill of materials
10. Physical map of TP8312 DEMO board
The Links: LP150X05-A2C1 LM170E03-TLJ6