MAX16928CGUP/V+T Maxim Integrated, MAX16928CGUP/V+T Datasheet - Page 17

• Manufacturer Part Number: MAX16928CGUP/V+T
• Description: LCD Drivers Automotive TFT Power Supply
• Manufacturer: Maxim Integrated

Specifications of MAX16928CGUP/V+T

• Rohs: yes

The voltage and current rise and fall times at the LXP
node are equal to t
time), t
and are determined as follows:
K
slew rates of the LXP node and are supply dependent.
Use
Use the lowest number of charge-pump stages possible
in supplying power to the positive voltage regulator.
Doing so minimizes the drain-source voltage of the inte-
grated pMOS switch and power dissipation. The power
dissipated in the switch is given as:
Ensure that the voltage on CP does not exceed the
CP overvoltage threshold as given in the
Characteristics
Use the lowest number of charge-pump stages possible
to provide the negative voltage to the negative-gate
Table 4. LXP Voltage and Current Slew Rates vs. Supply Voltage
Maxim Integrated
R-V
V
, K
Table 4
INA
3.3
R-I
5
F-V
(V)
P
(current rise time), and t
Automotive TFT-LCD Power Supply with Boost
, K
GH
to determine their values.
R-I
= (V
t
t
table.
R-V
F-V
, and K
R-V
CP
t
t
RISING VOLTAGE
=
=
R-I
F-I
Negative-Gate Voltage Regulator
(voltage rise time), t
V
V
- V
SLEW RATE,
Positive-Gate Voltage Regulator
=
K
=
SH
SH
F-I
R-V
I
I
GH
IN(DC,MAX)
IN(DC,MAX)
0.52
1.35
Converter and Gate Voltage Regulators
+
+
are the voltage and current
) × I
(V/ns)
V
V
K
K
K
K
SCHOTTKY
SCHOTTKY
R-V
R-I
F-I
F-V
LOAD(MAX)_GH
F-I
(current fall time),
F-V
FALLING VOLTAGE
(voltage fall
LXP VOLTAGE AND CURRENT SLEW RATES
Electrical
SLEW RATE,
K
F-V
1.7
2
(V/ns)
voltage regulator. Estimate the power dissipated in the
negative-gate voltage regulator using the following:
where V
bipolar transistor, and I
DRVN to the R
transistor, which is given by:
The power dissipated in the 1.8V/3.3V regulator controller
is given by:
where V
voltage of the external npn bipolar transistor, and I
the current sourced from DR to the base of the transistor.
I
where I
controller, and h
The total power dissipated in the package is the sum of
the losses previously calculated. Therefore, total power
dissipation can be estimated as follows:
Achieve maximum heat transfer by connecting the
exposed pad to a thermal landing pad and connecting
the thermal landing pad to a large ground plane through
thermal vias.
DR
is given by:
LOAD
BE
OUT_REG
P
RISING CURRENT
REG
P
is the base-emitter voltage of the external npn
GL
P
SLEW RATE,
K
T
is load current of the 1.8V/3.3V regulator
R-I
= (V
= (V
= P
BE
0.13
FE
0.3
I
(A/ns)
= 1.8V or 3.3V, V
DRVN
LXP
bias resistor and to the base of the
INA
is the current gain of the transistor.
INA
I
DR
+ P
- V
DRVN
+ |V
=
1.8V/3.3V Regulator Controller
=
R
OUT_REG
V
GH
BE
CN
BE
h
I
LOAD
FE
is the current sourced from
+ P
| - V
+
Total Power Dissipation
MAX16928
+
h
1
GL
I
FE
BE
FALLING CURRENT
GL
BE
- V
+1
) × I
+ P
SLEW RATE,
is the base-emitter
BE
K
F-I
REG
DRVN
) × I
0.38
0.44
(A/ns)
DR
DR
17
is