MAX16807AUI+ Maxim Integrated Products, MAX16807AUI+ Datasheet - Page 15

• Manufacturer Part Number: MAX16807AUI+
• Description: IC LED DRVR WT/RGB BCKLT 28TSSOP
• Manufacturer: Maxim Integrated Products
• Type: Backlight, White LED, RGB (Serial Interface)r

Specifications of MAX16807AUI+

• Constant Current: Yes
• Topology: Open Drain, PWM, Step-Down (Buck), SEPIC, Step-Up (Boost)
• Number Of Outputs: 8
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: RGB, White LED
• Frequency: 20kHz ~ 1MHz
• Voltage - Supply: 8 V ~ 26.5 V
• Voltage - Output: 36V
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP Exposed Pad, 28-eTSSOP, 28-HTSSOP
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 55mA
• Internal Switch(s): No
• Low Level Output Current: 55 mA
• Operating Supply Voltage: 8 V to 24 V
• Maximum Supply Current: 5 mA
• Maximum Power Dissipation: 2162 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: Lead free / RoHS Compliant

Table 1. 4-Wire Serial-Interface Truth Table
The MAX16807 also operates in a stand-alone mode
(see the Typical Operating Circuits ). For use with a
microcontroller, the MAX16807 features a 4-wire serial
interface using DIN, CLK, LE, OE inputs and DOUT as
a data output. This interface is used to write the LED
channels’ data to the MAX16807. The serial-interface
data word length is 8 bits, D0–D7. See Figure 3.
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 D7 is clocked in first,
followed by 7 more data bits, finishing with the LSB, D0.
CLK is the serial-clock input that shifts data at DIN into
the MAX16807’s 8-bit shift register on its rising edge.
LE is the latch enable input of the MAX16807 that trans-
fers data from the 8-bit shift register to its 8-bit output
latch (transparent latch). The data is latched on the
falling edge of LE (Figure 4). The fourth input (OE) pro-
vides output-enable control of the output drivers. When
OE is driven high, the outputs (OUT0–OUT7) are forced
to high impedance without altering the contents of the
output latches. Driving OE low enables the outputs to
follow the state of the output latches. OE is indepen-
dent of the operation of the serial interface operation.
Data can be shifted into the serial-interface shift regis-
ter and latched, regardless of the state of OE. DOUT is
the serial-data output that shifts data out from the
MAX16807’s 8-bit shift register on the rising edge of
L = Low Logic Level
H = High Logic Level
X = Don’t Care
P = Present State (Shift Register)
R = Previous State (Latched)
SERIAL
INPUT
DATA
DIN
H
L
X
CLOCK
INPUT
CLK
SHIFT REGISTER CONTENTS
D0 D1 D2 … Dn-1
R0 R1 R2 … Rn-1
P0
Switch-Mode Boost and SEPIC Controller
H
X
L
______________________________________________________________________________________
R0 R1 … Rn-2 Rn-1
R0 R1 … Rn-2 Rn-1
P1 P2 … Pn-1
X
Integrated 8-Channel LED Driver with
X
…
X
4-Wire Interface
LED Driver
Dn
Rn
Pn
X
INPUT
LOAD
LE
H
L
D0 D1 D2 … Dn-1 Dn
R0 R1 R2
P0 P1 P2
X
LATCH CONTENTS
X
CLK. Data at DIN propagates through the shift register
and appears at DOUT eight clock cycles later. Table 1
shows the 4-wire serial-interface truth table.
The MAX16807 uses an external resistor, R
the LED current for outputs OUT0–OUT7. The minimum
allowed value of R
currents to 55mA. The maximum allowed value of R
is 5kΩ (I
tance at SET is 100pF.
Use the following formula to set the output current:
where I
and the value for R
The MAX16807 contains an internal temperature sensor
that turns off all outputs when the die temperature
exceeds +165°C. The outputs are enabled again when
the die temperature drops below +140°C. Register con-
tents are not affected, so when a driver is overdissipat-
ing, the external symptom is the load LEDs cycling on
and off as the driver repeatedly overheats and cools,
alternately turning itself off and then back on again.
X
… Rn-1 Rn
… Pn-1 Pn
…
OUT_
OUT_
X
is the desired output current in milliamps
= 3.6mA) and maximum allowed capaci-
X
R
Selecting External Component
SET
BLANKING
R
SET
SET
SET
INPUT
OE
to Set LED Output Current
H
L
is in ohms.
is 330Ω, which sets the output
Overtemperature Cutoff
=
18 000
I
OUT
D0 D1 D2 …
P0 P1 P2
,
L
OUTPUT CONTENTS
CURRENT AT OUT_
_
L
L
…
…
SET
Dn-1 Dn
Pn-1 Pn
L
, to set
SET
15
L