HT7470 Просмотр технического описания (PDF) - Holtek Semiconductor

Номер в каталоге

Компоненты Описание

производитель

HT7470

Fast Battery Charger

Holtek Semiconductor 

HT7470

Indicator

The HT7470 can indicate all the battery’s states

with the indicators LED1, LED2 and the buzzer

(BZ, BZ). Each state is represented in the fol-

lowing table.

Mode

LED1* LED2* Buzzer

Charging

on

off

off

Warming

on

off

off

Discharging

on

on

off

Full charge

Flash

(slow)

off

off

Warm-up

waiting

period

Flash

(fast)

off

off

Abnormal

Flash

Flash

Flash tone

(1 minute)

Standby

off

off

off

* Note: LED1 and LED2 are active low.

Input RC-Network

The HT7470 is a universal fast charge control-

ler for NiCd batteries. It can be used to charge

batteries of any rated voltage by adjusting the

CR resistance of the RC-network and the inte-

gral time constant of the A/D converter. The

RC-network is configured as shown and the CR

resistance is listed in the table. Note that the

integral time constant of the A/D converter is

38.54ms and the minimum battery rated volt-

age is 2.4V in this case.

CR =

Battery rated voltage – 2.4

2.4

∗ 2K

Input RC-Network

If the minimum battery rated voltage is 1.2V

the CR1 resistance must be 1K and the integral

time constant of the A/D converter must be

77.08ms. The CR resistance can be calculated

by the following equation

CR =

Battery rated voltage – 1.2

1.2

∗ 1K

5

25th Aug ’94

Share Link: