MAX16810ATU+T Maxim Integrated Products, MAX16810ATU+T Datasheet - Page 13

• Manufacturer Part Number: MAX16810ATU+T
• Description: IC LED DRVR WT/RGB BCKLT 38-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Backlight, White LED, RGB (Serial Interface)r

Specifications of MAX16810ATU+T

• Constant Current: Yes
• Topology: *
• Number Of Outputs: 16
• 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: 38-TQFN Exposed Pad
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 55mA
• Internal Switch(s): No
• Low Level Output Current: 6 mA
• High Level Output Current: 1.8 mA
• Operating Supply Voltage: 3 V to 5.5 V
• Maximum Supply Current: 5 mA
• Maximum Power Dissipation: 2857 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 1b. OUT_ _ Driver Internal Diagram
The advantages of current-mode control over voltage-
mode control are twofold. First, there is the feed-for-
ward characteristic brought on by the controller’s ability
to adjust for variations in the input voltage on a cycle-
by-cycle basis. Second, the stability requirements of
the current-mode controller are reduced to that of a sin-
gle-pole system unlike the double pole in the voltage-
mode control scheme. The MAX16809 uses a
current-mode control loop where the output of the error
amplifier is compared to the current-sense voltage
(V
inverting input of the CPWM comparator, the output of
the comparator is low and the switch is turned on at
each clock pulse. When the current-sense signal is
higher than the inverting input of the CPWM compara-
tor, the output is high and the switch is turned off.
The turn-on supply voltage for the MAX16809 is 8.4V
(typ). Once V
There is a 0.8V of hysteresis from the turn-on voltage to
the UVLO threshold. Once V
MAX16809 operates with V
goes below 7.6V (typ), the device is in UVLO. When in
UVLO, the quiescent supply current into V
to 32μA (typ), and OUT and REF are pulled low.
OUT drives an external n-channel MOSFET and swings
from AGND to V
absolute maximum V
OUT is a push-pull output with the on-resistance of the
CS
1.23V
). When the current-sense signal is lower than the
R
1.23
CC
EST
SET
68W/L
CC
reaches 8.4V, the reference powers up.
Switch-Mode Boost and SEPIC Controller
Undervoltage Lockout (UVLO)
Switch-Mode Controller
______________________________________________________________________________________
. Ensure that V
Current-Mode Control Loop
GS
Integrated 16-Channel LED Driver with
V+
rating of the external MOSFET.
CC
945R
W/L
down to 7.6V. Once V
CC
CC
reaches 8.4V, the
MOSFET Driver
MAX16809
remains below the
PGND
CC
R
falls back
OUT_ _
CC
pMOS typically 3.5Ω and the on-resistance of the nMOS
typically 4.5Ω. The driver can source 2A and sink 1A typi-
cally. This allows for the MAX16809 to quickly turn on and
off high gate-charge MOSFETs. Bypass V
more 0.1μF ceramic capacitors to AGND, placed close to
V
MOSFET depends on the total gate charge (Q
operating frequency of the converter. The power dissipa-
tion in the MAX16809 is a function of the average output
drive current (I
culate the power dissipation in the device due to I
where I
Typical Operating Characteristics for the operating
supply current at a given frequency.
The MAX16809 includes an internal error amplifier. The
inverting input is at FB and the noninverting input is
internally connected to a 2.5V reference. Set the output
voltage using a resistive divider between output of the
converter V
mula to set the output voltage:
where V
The oscillator frequency is programmable using an
external capacitor and a resistor at RTCT (see R
C
from RTCT to the 5V reference (REF), and C
nected from RTCT to AGND. REF charges C
R
through an 8.3mA internal current sink until C
reaches 1.1V, at which time C
through R
the charge and discharge times of C
charge time as follows:
where t
Farads (F).
The discharge time is then:
where t
Farads (F).
CC
T
T
t
in the Typical Operating Circuits ). R
until its voltage reaches 2.8V. C
D
. The average current sourced to drive the external
= (R
CC
FB
C
D
T
T
is in seconds, R
is in seconds, R
= 2.5V.
OUT
is the operating supply current. See the
again. The oscillator’s period is the sum of
x C
DRIVE
PD = (I
T
, FB, and AGND. Use the following for-
V
x 1000) / [(4.88 x R
OUT
I
t
DRIVE
C
). Use the following equation to cal-
= 0.57 x R
DRIVE
=
⎛
⎝ ⎜
= (Q
1
+
+ I
T
T
R
R
G
1
2
in ohms (Ω), and C
in ohms (Ω), and C
CC
T
x f
⎞
⎠ ⎟
T
x C
x V
) x V
SW
is allowed to charge
T
FB
T
Error Amplifier
)
T
) - (1.8 x 1000)]
CC
then discharges
T
. Calculate the
T
CC
is connected
Oscillator
with one or
T
T
’s voltage
T
DRIVE
through
G
is con-
T
) and
and
T
T
13
:
in
in