MAX6951CEE+ Maxim Integrated Products, MAX6951CEE+ Datasheet - Page 9

• Manufacturer Part Number: MAX6951CEE+
• Description: IC DRVR DSPL LED SRL 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6951CEE+

• Display Type: LED
• Configuration: 7 Segment
• Interface: 3-Wire Serial
• Digits Or Characters: 8 Digits
• Current - Supply: 10mA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP Exposed Pad, 16-eQSOP , 16-HQSOP
• Number Of Digits: 8
• Number Of Segments: 64
• Low Level Output Current: 400000 uA
• High Level Output Current: - 50000 uA
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Supply Current: 15000 uA
• Maximum Power Dissipation: 667 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 4. Initial Power-Up Register Status
The scan-limit register sets how many digits are dis-
played, from one to eight digits. It is possible to set the
MAX6950 (the five-digit part) to scan six, seven, or
eight digits. The MAX6951 set to eight digits displays
five digits less brightly than if it had been set to scan
five digits, but the brightness would match that of a
MAX6951 used in the same system if the Intensity reg-
isters are set to the same value. For example, consider
an 11-digit requirement. This can be served by using a
MAX6950 to drive five digits plus a MAX6951 to drive
six digits. Both parts are configured to drive six digits to
ensure the brightness is the same.
The digits are displayed in a multiplexed manner with a
typical display scan rate of 1kHz with five digits dis-
played or 625Hz with eight digits displayed with f
4MHz. Since the number of scanned digits affects the
display brightness, the Scan-Limit register should not
be used to blank portions of the display (such as for
leading-zero suppression). Table 12 lists the scan-limit
register format.
Digital control of display brightness is provided by an
internal pulse-width modulator, which is controlled by the
lower nibble of the intensity register (Figure 4). The mod-
ulator scales the average segment current in 16 steps
from a minimum of 15/16 down to 1/16 of the peak cur-
rent. The minimum interdigit blanking time is set to 1/16
of a cycle. See Table 13 for Intensity register format.
Configuration
Display Test
REGISTER
Scan Limit
Intensity
Decode
Digit 0
Digit 1
Digit 2
Digit 3
Digit 4
Digit 5
Digit 6
Digit 7
No decode for digits 7–0
1/16 (min on)
Display 5 digits: 0 1 2 3 4
S hutd ow n enab l ed /b l i nk
sp eed i s sl ow /b l i nk d i sab l ed
Normal operation
Blank digit, both planes
Blank digit, both planes
Blank digit, both planes
Blank digit, both planes
Blank digit, both planes
Blank digit, both planes
Blank digit, both planes
Blank digit, both planes
POWER-UP CONDITION
_______________________________________________________________________________________
Scan-Limit Register
Serially Interfaced, +2.7V to +5.5V,
Intensity Register
5- and 8-Digit LED Display Drivers
CODE (HEX)
ADDRESS
0x01
0x02
0x03
0x04
0x07
0x60
0x61
0x62
0x63
0x64
0x65
0x66
0x67
OSC
=
D7
0
X
X
X
X
0
0
0
0
0
0
0
0
The decode mode register sets hexadecimal code
(0–9, A–F) or no-decode operation for each digit. Each
bit in the register corresponds to one digit. A logic high
selects hexadecimal code font decoding for that digit,
while logic low bypasses the decoder. Digits may be
set for decode or no-decode in any combination.
Examples of the decode mode control register format
are shown in Table 14.
When the hexadecimal code-decode mode is used, the
decoder looks only at the lower nibble of the data in the
digit register (D3–D0), disregarding bits D6–D4. D7,
which sets the decimal point (SEG DP), is independent
of the decoder, and is positive logic (D7 = 1 turns the
decimal point on). Table 15 lists the hexadecimal code
font. When no-decode is selected, data bits D7–D0 cor-
respond to the segment lines of the MAX6950/
MAX6951. Table 15 shows the one-to-one pairing of
each data bit to the appropriate segment line.
The MAX6950/MAX6951 use a digit register to store the
data that the user wishes to display on the LED digits.
These digit registers are implemented by two planes of
8-byte, dual-port SRAM, called P0 and P1. The digit
registers are dual port to enable them to be written to
through the SPI interface, asynchronous to being read
to multiplex the display.
D6
0
X
X
X
X
0
0
0
0
0
0
0
0
D5
0
X
X
X
X
0
0
0
0
0
0
0
0
REGISTER DATA
D4
X
X
X
0
0
0
0
0
0
0
0
0
0
Display Digit Registers
Decode Mode Register
D3
0
0
X
0
X
0
0
0
0
0
0
0
0
D2
0
0
1
0
X
0
0
0
0
0
0
0
0
D1
X
0
0
0
0
0
0
0
0
0
0
0
0
D0
0
0
0
0
0
0
0
0
0
0
0
0
0
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