ICM7228AIBIZ Intersil, ICM7228AIBIZ Datasheet - Page 10

• Manufacturer Part Number: ICM7228AIBIZ
• Description: IC DRIVER DECODER 8DGT CA 28SOIC
• Manufacturer: Intersil

Specifications of ICM7228AIBIZ

• Display Type: LED
• Configuration: 7 Segment
• Digits Or Characters: 8 Digits
• Current - Supply: 200µA
• Voltage - Supply: 4 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -

Detailed Description
System Interfacing and Data Entry Modes,
ICM7228A and ICM7228B
The ICM7228A/B devices are compatible with the
architectures of most microprocessor systems. Their fast
switching characteristics makes it possible to access them as
a memory mapped I/O device with no wait state necessary in
most microcontroller systems. All the ICM7228A/B inputs,
including MODE, feature a 250ns minimum setup and 0ns
hold time with a 200ns minimum WRITE pulse. Input logic
levels are TTL and CMOS compatible. Figure 9 shows a
generic method of driving the ICM7228A/B from a
microprocessor bus. To the microprocessor, each device
appears to be 2 separate I/O locations; the Control Register
and the Display RAM. Selection between the two is
accomplished by the MODE input driven by address line A0.
Input data is placed on the lD0 - lD7 lines. The WRITE input
acts as both a device select and write cycle timing pulse. See
Figure 1 and Switching Specifications Table for write cycle
timing parameters.
The ICM7228A/B have three data entry modes: Control
Register update without RAM update, sequential 8-digit
update and single digit update. In all three modes a control
word is first written by pulsing the WRITE input while the
PIN NO.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
9
HEXA/CODE
B/SHUTDOWN
DA2
ID1
ID0
ID2
ID3
DIGIT 1
DlGlT 2
DIGIT 5
DlGlT 8
V
DIGIT 4
DlGlT 7
DlGlT 6
DIGlT 3
SEG f
SEG d
SEG g
SEG a
V
DD
SS
NAME
10
TABLE 3. ICM7228C PIN ASSIGNMENTS AND DESCRIPTIONS (Continued)
FUNCTION
Output
Supply
Output
Output
Supply
Input
Input
Input
Three Level Input. Display Function Control: High, Hexadecimal Decoding; Float, Code B
Decoding; Low, Oscillator, and Display Disabled.
Digit Address Input, Bit 3, MSB.
Display Data Inputs.
LED Display Digits 1, 2, 5 and 8 Drive Lines.
Device Positive Power Supply Rail.
LED Display Digits 4, 7, 6 and 3 Drive Lines.
LED Display Segments f, d, g and a Drive Lines.
Device Ground or Negative Power Supply Rail.
ICM7228
MODE input is high, thereby latching data into the Control
Register. The logic level of individual bits in the Control
Register select Shutdown, Decode/No Decode, Hex/Code B,
RAM bank A/B and Display RAM digit address as shown in
Tables 1 and 2.
The ICM7228A/B Display RAM is divided into 2 banks, called
bank A and B. When using the Hexadecimal or code B display
modes, these RAM banks can be selected separately. This
allows two separate sets of display data to be stored and
displayed alternately. Notice that the RAM bank selection is not
possible in No-Decode mode, this is because the display data
in the No-Decode mode has 8 bits, but in Decoded schemes
(Hex/Code B) is only 4 bits (lD0 - lD3 data). It should also be
mentioned that the decimal point is independent of selected
bank, a turned on decimal point will remain on for either bank.
Selection of the RAM banks is controlled by lD3 input. The lD3
logic level (during Control Register update) selects which bank
of the internal RAM to be written to and/or displayed.
Control Register Update without RAM Update
The Control Register can be updated without changing the
display data by a single pulse on the WRITE input, with MODE
high and DATA COMING low. If the display is being decoded
(Hex/Code B), then the value of lD3 determines which RAM
bank will be selected and displayed for all eight digits.
DESCRIPTION