US 12,243,470 B2
LED display driver chip with analog and digital units and method for driving the same
Zhaoyu Jiang, Nanjing (CN); Ruoping Zhang, Nanjing (CN); Mao Zhao, Nanjing (CN); and Junjie Chen, Nanjing (CN)
Assigned to PURESEMI Co., Ltd., Nanjing (CN)
Appl. No. 17/802,026
Filed by PURESEMI Co., Ltd., Nanjing (CN)
PCT Filed Apr. 21, 2022, PCT No. PCT/CN2022/088159
§ 371(c)(1), (2) Date Jul. 20, 2023,
PCT Pub. No. WO2023/134051, PCT Pub. Date Jul. 20, 2023.
Claims priority of application No. 202210042638.6 (CN), filed on Jan. 14, 2022.
Prior Publication US 2024/0221605 A1, Jul. 4, 2024
Int. Cl. G09G 3/32 (2016.01); G09G 3/20 (2006.01)
CPC G09G 3/32 (2013.01) [G09G 3/2011 (2013.01); G09G 3/2014 (2013.01); G09G 3/2077 (2013.01); G09G 2310/027 (2013.01); G09G 2320/0233 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A light-emitting diode (LED) display driver chip, comprising an analog unit and a digital unit,
wherein the analog unit comprises a current reference unit, a constant current output array unit, and a Digital to Analog Converter (DAC) small current precision circuit unit configured to generate a DAC small current and complete precise replication of the DAC small current,
wherein the digital unit comprises an image parameter writing unit, a static random access memory (SRAM) unit, a configurable register unit, and a pulse amplitude modulation (PAM) and pulse width modulation (PWM) adjustment unit configured to perform PAM and PWM adjustment,
wherein the PAM and PWM adjustment unit in the digital unit is connected to the analog unit,
wherein an output reference current of the current reference unit is outputted from the constant current output array unit through the DAC small current precision circuit unit in the analog unit,
wherein the DAC small current precision circuit unit comprises a DAC small current precision module, and
wherein a circuit of the DAC small current precision module comprises several N-channel Metal-Oxide-Semiconductor (NMOS) transistors connected in parallel, gates of the NMOS transistors are all connected to an input signal D<n> through switches, drains are all connected to an input voltage, and sources are grounded.