Datasheet
MAX6960–MAX6963
4-Wire Serially Interfaced
8 x 8 Matrix Graphic LED Drivers
28
Maxim Integrated
Overtemperature Fault Detection
The MAX6960 contains an overtemperature (OT) detec-
tion circuit, which trips at a die temperature of typically
+150°C. The OT event is latched, and is readable in the
fault and device ID register (Table 32). When the OT
trips, the MAX6960 shutdown bit in the configuration
register (Table 15) is cleared, and the driver goes into
shutdown. Data is not lost; the effect is the same as the
user setting the shutdown bit. The user can attempt to
set the shutdown bit at any time. However, if the driver
is still over temperature, then the attempt to set the
shutdown bit is ignored. The OT fault flag is NOT auto-
matically cleared when the device cools, or when the
device is taken out of shutdown.
The fault and device ID register is cleared on power-
up, and can also be cleared by writing to it. The fault
flags are NOT cleared by a read. When writing the fault
and device ID register, the data written is ignored; all
fault flags are cleared, including the LED flags. It is
possible to clear all MAX6960s on a bus by performing
a global write to the fault and device ID register.
Applications Information
Setting LED Drive Current
The MAX6960 can be configured for pretrimmed 20mA
or 40mA LED current, or a 20mA to 40mA adjustable
current, on a digit-by-digit basis by the RISET0 and
RISET1 pin connections (Figures 13 and 14). The digit
intensity registers can be used to digitally adjust the
segment current, again on a digit-by-digit basis, by
controlling the PWM. Some applications best use one
or the other technique; some applications may require
the flexibility of both.
V
REF
TO RED
LED DRIVERS
R
INT
R
INT
RISET0
42
V
REF
TO GREEN
LED DRIVERS
R
INT
R
INT
RISET1
43
MAX6960
MAX6961
MAX6962
MAX6963
Figure 13. RISET0 and RISET1 Internal Architecture
MAX6960–
MAX6963
MAX6960–
MAX6963
MAX6960–
MAX6963
42
43
RISET0
RISET1
42
43
RISET0
RISET1
42
43
RISET0
RISET1
NO CONNECTION
NO CONNECTION
R0
R1
SETTING LED CURRENT
TO 40mA
ADJUSTABLE LED CURRENT
20mA
SETTING LED CURRENT
TO 20mA
Figure 14. RISET0 and RISET1 Pin Connections