UPD16681 查看數據表（PDF） - NEC => Renesas Technology

零件编号

产品描述 (功能)

比赛名单

UPD16681

LCD CONTROLLER/DRIVER FOR DOT MATRIX DISPLAY OF JIS LEVEL 1 AND JIS LEVEL 2 KANJI SETS

NEC => Renesas Technology 

µPD16681

4. POWER SUPPLY CIRCUIT

A switchable (3x or 4x) boost circuit is included to generate a current for driving the LCD. A connection to a boost-

related capacitor is used to switch the boost circuit’s setting.

The VEXT pin (H: external, L: internal) is used to switch between using an external LCD driver power supply or the

on-chip boost circuit.

4.1 Boost Circuit

When using the internal power supply, connect the boost-related capacitor between C1+ and C1−, C2+ and C2−, and

C3+ and C3−. Also, connect the capacitor for level stabilization between VLCD and VSS, and set VEXT low to boost the

potential between VDD and VSS from 3 to 4 times.

Since the boost circuit uses signals from the internal oscillation circuit, the oscillation circuit must be operating. The

relation between the boosted voltage and the potential is described below.

The C1+, C1−, C2+, C2−, C3+, C3− and VDD pins all relate to the boost circuit, so the wire impedance should be

minimized.

Figure 4-1. 3x and 4x Boost Mode

VLCD = 4VDD = 12 V

(During 4x boost mode)

VLCD = 3VDD = 9 V

(During 3x boost mode Note )

VDD = 3 V

VSS = 0 V

Note When set for 3x boost, connect boost-related capacitors between C2− and C3+ and C1+ and C1−.

8

Data Sheet S13104EJ5V0DS00

Share Link: