MAX6971ANG+ Maxim Integrated Products, MAX6971ANG+ Datasheet - Page 7
![IC LED DRIVER LINEAR 24-DIP](/photos/6/58/65847/175-24-dip_sml.jpg)
MAX6971ANG+
Manufacturer Part Number
MAX6971ANG+
Description
IC LED DRIVER LINEAR 24-DIP
Manufacturer
Maxim Integrated Products
Type
Linear (Serial Interface)r
Datasheet
1.MAX6971ANG.pdf
(12 pages)
Specifications of MAX6971ANG+
Constant Current
Yes
Topology
16-Bit Shift Register, Open Drain, PWM
Number Of Outputs
16
Internal Driver
Yes
Type - Primary
General Purpose
Voltage - Supply
3 V ~ 5.5 V
Voltage - Output
36V
Mounting Type
Through Hole
Package / Case
24-DIP (0.300", 7.62mm)
Operating Temperature
-40°C ~ 125°C
Current - Output / Channel
55mA
Internal Switch(s)
No
Number Of Segments
32
Low Level Output Current
60000 uA
Operating Supply Voltage
3 V to 5.5 V
Maximum Supply Current
25 mA
Maximum Power Dissipation
1067 mW
Maximum Operating Temperature
+ 125 C
Mounting Style
Through Hole
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Frequency
-
Efficiency
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
The MAX6971 LED driver comprises a 4-wire serial
interface driving 16 constant-current-sinking, open-
drain output ports. The outputs drive LEDs in either
static or multiplex applications (Figure 1). The constant-
current outputs are guaranteed for current accuracy
not only with chip-supply voltage variations (5V ±10%
and 3V to 5.5V), but also over a realistic range of driver
output voltage drop (0.8V to 2.5V). The drivers use cur-
rent-sensing feedback circuitry (not simple current mir-
rors) to ensure very small current variations over the full
allowed range of output voltage (see the Typical
Operating Characteristics).
The 4-wire serial interface comprises a 16-bit shift reg-
ister and a 16-bit transparent latch. The shift register is
written through a clock input, CLK, and a data input,
DIN, and the data propagates to a data output, DOUT.
The data output allows multiple drivers to be cascaded
and operated together. The contents of the 16-bit shift
register are loaded into the transparent latch through a
latch-enable input, LE. The latch is transparent to the
shift register outputs when high, and latches the current
state on the falling edge of LE.
Figure 2. 4-Wire Serial-Interface Timing Diagram
DOUT
OUT_
CLK
DIN
OE
LE
16-Port, 36V Constant-Current LED Driver
_______________________________________________________________________________________
Detailed Description
t
DS
D15
t
DH
t
CL
t
OEL
D14
t
f
t
t
CH
OEW
80%
20%
Each driver output is an open-drain, constant-current
sink that should be connected to the cathode of either
a single LED or a series string of multiple LEDs. The
LED anode can be connected to a supply voltage of up
to 36V, independent of the MAX6971 supply, V+. The
constant-current capability is up to 55mA per output,
set for all eight outputs by an external resistor, R
The serial interface on the MAX6971 is a 4-wire serial
interface using four inputs (DIN, CLK, LE, OE) and a
data output (DOUT). This interface is used to write dis-
play data to the MAX6971. The serial-interface data
word length is 16 bits, D0–D15. See Figure 2.
The functions of the five interface pins are as follows.
DIN is the serial-data input, and must be stable when it
is sampled on the rising edge of CLK. Data is shifted in,
MSB first. This means that data bit D15 is clocked in
first, followed by 15 more data bits finishing with the
LSB, D0.
t
OEH
D1
t
r
t
DO
t
CP
.
D0
t
LS
4-Wire Serial Interface
D7
t
t
LW
LF
SET
.
7