Datasheet
MAX6952
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5
✕
7 Matrix LED Display Driver
______________________________________________________________________________________ 15
REGISTER DATA
FONT
CHARACTER
ADDRESS
CODE (HEX)
REGISTER
DATA (HEX)
D7 D6 D5 D4 D3 D2 D1 D0
RAM00 0x05 0x80 1 0 0 0 0 0 0 0
RAM01 0x05 0x85 1 0 0 0 0 1 0 1
RAM02 0x05 0x8A 1 0 0 0 1 0 1 0
RAM03 0x05 0x8F 1 0 0 0 1 1 1 1
RAM04 0x05 0x94 1 0 0 1 0 1 0 0
RAM05 0x05 0x99 1 0 0 1 1 0 0 1
RAM06 0x05 0x9E 1 0 0 1 1 1 1 0
RAM07 0x05 0xA3 1 0 1 0 0 0 1 1
RAM08 0x05 0xA8 1 0 1 0 1 0 0 0
RAM09 0x05 0xAD 1 0 1 0 1 1 0 1
RAM10 0x05 0xB2 1 0 1 1 0 0 1 0
RAM11 0x05 0xB7 1 0 1 1 0 1 1 1
RAM12 0x05 0xBC 1 0 1 1 1 1 0 0
RAM13 0x05 0xC1 1 1 0 0 0 0 0 1
RAM14 0x05 0xC6 1 1 0 0 0 1 1 0
RAM15 0x05 0xCB 1 1 0 0 1 0 1 1
RAM16 0x05 0xD0 1 1 0 1 0 0 0 0
RAM17 0x05 0xD5 1 1 0 1 0 1 0 1
RAM18 0x05 0xDA 1 1 0 1 1 0 1 0
RAM19 0x05 0xDF 1 1 0 1 1 1 1 1
RAM20 0x05 0xE4 1 1 1 0 0 1 0 0
RAM21 0x05 0xE9 1 1 1 0 1 0 0 1
RAM22 0x05 0xEE 1 1 1 0 1 1 1 0
RAM23 0x05 0xF3 1 1 1 1 0 0 1 1
Table 17. User-Definable Font Pointer Base Address Table
The recommended value of R
SET
is the minimum
allowed value since it sets the display driver to the
maximum allowed segment current. R
SET
can be set to
a higher value to set the segment current to a lower
peak value where desired. The user must also ensure
that the peak current specifications of the LEDs con-
nected to the driver are not exceeded.
The effective value of C
SET
includes not only the actual
external capacitor used, but also the stray capacitance
from OSC to GND. This capacitance is usually in the
1pF to 5pF range, depending on the layout used.
Display-Test Register
The display-test register switches the drivers between
one of two modes: normal and display test. Display-test
mode turns all LEDs on by overriding, but not altering,
all control and digit registers (including the shutdown
register). In display-test mode, eight digits are scanned
and the duty cycle is 7/16 (half power). Table 23 lists
the display-test register format.
Applications Information
Choosing Supply Voltage to Minimize
Power Dissipation
The MAX6952 drives a peak current of 40mA into LEDs
with a 2.4V forward-voltage drop when operated from a
supply voltage of at least 3.0V. The minimum voltage
drop across the internal LED drivers is, therefore (3.0V -
2.4V) = 0.6V. If a higher supply voltage is used, the dri-
ver absorbs a higher voltage, and the driver’s power
dissipation increases accordingly. However, if the LEDs
used have a higher forward voltage drop than 2.4V, the
supply voltage must be raised accordingly to ensure
that the driver always has at least 0.6V headroom.