Pad Description

Pad No.

Pad Name

I/O

Description

1CS

I

Chip selection input with pull-high resistor. When the CS is logic high, the

data and command read from or written to the HT16220 are disabled. The

serial interface circuit is also reset But if the CS is at logic low level and is

input to the CS pad, the data and command transmission between the

host controller and the HT16220 are all enabled.

2RD

I

READ clock input with pull-high resistor. Data in the RAM of the HT16220

are clocked out on the falling edge of the RD signal. The clocked out data

will appear on the data line. The host controller can use the next rising

edge to latch the clocked out data.

3WR

I

WRITE clock input with pull-high resistor. Data on the DATA line are

latched into the HT16220 on the rising edge of the WR signal.

4

DATA

I/O

Serial data input or output with pull-high resistor

5

VSS

¾

Negative power supply, ground

6

VDD

¾

Positive power supply

7

VLCD

I

LCD operating voltage input pad.

8

IRQ

O

Time base or watchdog timer overflow flag, NMOS open drain output.

9, 10

BZ, BZ

O

2kHz or 4kHz tone frequency output pair

11

OSCO

O

Crystal oscillator output pin

12

OSCI

I

Crystal oscillator input pin

13~15

T1~T3

I

Not connected

16~23

COM0~COM7

O

LCD common outputs

24~55

SEG0~SEG31

O

LCD segment outputs

Absolute Maximum Ratings

Supply Voltage .........................................

-0.3V to 5.5V

Storage Temperature ...........................

-50°Cto125°C

Operating Temperature ..........................

-40°Cto85°C

Note: These are stress ratings only. Stresses exceeding the range specified under

²Absolute Maximum Ratings² may

cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed

in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.

D.C. Characteristics

Ta=25

°C

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Conditions

Operating Voltage

¾¾

2.7

¾

5.2

V

Operating Current

3V

No load or LCD ON

Crystal oscillator

¾¾

50

mA

5V

¾¾

65

mA

Operating Current

3V

No load or LCD OFF

Crystal oscillator

¾¾

20

mA

5V

¾¾

30

mA

Standby Current

3V

No load, Power down mode

¾

18

mA

5V

¾

216

mA

Input Low Voltage

3V

DATA, WR,CS,RD

0

¾

0.6

V

5V

0

¾

1.0

V

HT16220

Rev. 1.90

5

October 12, 2009

PATENTED