MAX6967ATE+ Maxim Integrated Products, MAX6967ATE+ Datasheet - Page 25
![IC LED DRIVER LINEAR 16-TQFN](/photos/6/66/66625/16-tqfn_exp_pad_21-0136_sml.jpg)
MAX6967ATE+
Manufacturer Part Number
MAX6967ATE+
Description
IC LED DRIVER LINEAR 16-TQFN
Manufacturer
Maxim Integrated Products
Type
Linear (Serial Interface)r
Datasheet
1.MAX6966ATE.pdf
(29 pages)
Specifications of MAX6967ATE+
Constant Current
Yes
Topology
Open Drain, PWM
Number Of Outputs
10
Internal Driver
Yes
Type - Primary
Backlight
Type - Secondary
RGB, White LED
Frequency
270kHz ~ 450kHz
Voltage - Supply
2.25 V ~ 3.6 V
Voltage - Output
7V
Mounting Type
Surface Mount
Package / Case
16-TQFN Exposed Pad
Operating Temperature
-40°C ~ 125°C
Current - Output / Channel
20mA
Internal Switch(s)
Yes
Number Of Segments
10
Low Level Output Current
21.1 mA
Operating Supply Voltage
2.25 V to 3.6 V
Maximum Supply Current
730 uA
Maximum Power Dissipation
1176 mW
Maximum Operating Temperature
+ 125 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Efficiency
-
Lead Free Status / Rohs Status
Details
Figure
LTST-C170TBKT 3.0V blue LED as the LED supply volt-
age is varied from 2.5V to 7V. The LED currents shown
are for ports programmed for 10mA and 20mA constant
current, swept over a 2.5V to 7V LED supply voltage
range. It can be seen that the LED forward voltage falls
with current, allowing the LED current to fall gracefully,
not abruptly, in brownout. In practice, the LED current
drops to 6mA to 7mA at a 3V LED supply voltage,
which is an acceptable performance at end-of-life in
many backlight applications.
The open-drain output architecture allows the ports to
level translate the outputs to higher or lower voltages
than the MAX6966/MAX6967 supply. An external pullup
resistor can be used on any output to convert the high-
impedance logic-high condition to a positive voltage
level. The resistor can be connected to any voltage up
to 7V. When using a pullup on a constant-current out-
put, select the resistor value to sink no more than a few
hundred µA in logic-low condition. This ensures that the
current sink output saturates close to GND. For inter-
facing CMOS inputs, a pullup resistor value of 220kΩ is
a good starting point. Use a lower resistance to
improve noise immunity in applications where power
consumption is less critical, or where a faster rise time
is needed for a given capacitive load.
Figure
13. LED Brownout
10-Port Constant-Current LED Drivers and I/O
13 shows the typical current sunk by a LITEON
______________________________________________________________________________________
3.05
3.00
2.95
2.90
2.85
2.80
2.75
2.70
2.65
2.60
2.55
2.50
Expanders with PWM Intensity Control
Output Level Translation
2.5
3.0
3.5 4.0 4.5
VLED vs. VLED SUPPLY
VLED SUPPLY (V)
5.0 5.5
6.0
6.5
7.0
The stagger option, when selected, applies to all ports
configured as constant-current outputs. The 10 ports’
PWM cycles are separated to eight evenly spaced start
positions
fewer than 10 ports are used as constant-current out-
puts by allocating the ports with the most appropriate
start positions. If eight constant-current outputs are
needed, choose P0–P7 because these all have differ-
ent PWM start positions. If four constant-current outputs
are needed, choose P0, P2, P4, P6 or P1, P3, P5, P7
because the PWM start positions are evenly spaced. In
general, choose the ports that spread the PWM start
positions as evenly as possible. This optimally spreads
out the current demand from the ports’ load supply.
An I/O port can be used to automatically generate a
shutdown/run output from the MAX6966/MAX6967. The
shutdown/run output is active low when the
MAX6966/MAX6967 are in run mode, hold-off, fade-off,
or ramp-up, and go high automatically when the
MAX6966/MAX6967 finally enter shutdown after fade-
off. Program the port’s output register to value 0x00,
which puts the output into static constant-current mode
(Table
half current
a 220kΩ pullup resistor to this port.
20
18
16
14
12
10
8
6
4
2
0
2.5
6). Program the port’s output current register to
3.0
(Figure
Generating a Shutdown/Run Output
3.5 4.0 4.5
ILED vs. VLED SUPPLY
(Table
VLED SUPPLY (V)
Using Stagger with Fewer Ports
3). This phasing can be optimized if
7) to minimize operating current. Fit
5.0 5.5
6.0
6.5
7.0
25