E7765AXF Semtech, E7765AXF Datasheet - Page 8

• Manufacturer Part Number: E7765AXF
• Manufacturer: Semtech

Specifications of E7765AXF

• Lead Free Status / Rohs Status: Not Compliant

Computing the Driver Output Voltage Range
The output voltage range of the driver at the DOUT pin is
defined by two fundamental calculations. First is the rela-
tionship to the power supply voltages at the device (VCC
and VEE) and second to the range of programmability of
the DVH and DVL input voltages. Remaining in the calcu-
lated output voltage range is required to maintain all the
DC and AC accuracy specifications for the driver function.
The DOUT range relative to the power supply voltages is
straightforward and depicted in the following figure at the
output of the driver. The required DOUT range must com-
ply with the noted headrooms to the VCC and VEE power
supplies. Headrooms larger than noted is also acceptable
but must remain within the power supply recommended
operating ranges.
The DOUT range is also dependant on the allowable pro-
gramming voltages at the DVH and DVL inputs. Each of
these inputs have similar requirements for power supply
headrooms as DOUT does. These headrooms are also
depicted in the figure. Furthermore, the DVH/L inputs will
have voltage offsets and gain error specifications. These
Application Information
TEST AND MEASUREMENT PRODUCTS
©
2006 Semtech Corp. , Rev. 11, 7/18/06
3.5V
4.0V
D
V
H
D
V
or
L
T
4.0V
3.5V
VCC
VEE
DVH
DVL
DOUT
O
D
U
T
3.7V
3.8V
8
specifications require that the DVH/L input programming
range be greater than the required DOUT voltage range if
the worst case offset and gain figures are used. The equa-
tion for the resulting minimum and maximum voltage at
DOUT is;
Solving for VIN;
To solve for the range of V
required. For example, if we choose -2.0V for the minimum
end and +6.5V for the maximum end of V
set min/max of -100mV/+100mV and a minimum gain of
0.975 the equations solve as;
For -2.0V;
For +6.5V;
These resulting V
room requirements previously mentioned as well as the
absolute (relative to ground) voltage limitations specified
in the DC specifications data.
Com
Com
Com
Com
Computing Maximum P
The diagram below shows the power consumption of the
E7765 as a function of power supply and performance
bias settings.
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
puting Maximum P
puting Maximum P
puting Maximum P
puting Maximum Po o o o o w w w w w er Consum
V
V
V
V
DOUT(MIN/MAX)
IN
IN(-2V)
IN(+6.5V)
= [ V
Min Supplies
= [ -2.0V – 100mV ] / 0.975 = -2.154V
= [ +6.5V + 100mV ] / 0.975 = +6.769V
DOUT(MIN/MAX)
Covers Complete Range of Supplies (All PON=1)
High Performance
IN
values then need to meet the head-
= V
OFFSET(MIN/MAX)
Power Dissipation
+ V
er Consum
er Consum
er Consumption
er Consum
IN
Typ Supplies
, first select the Vout ranges
OFFSET(MIN/MAX)
Lower Performance
+ [ V
ption
ption
ption
ption
IN
] / GAIN
* GAIN
DOUT
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Max Supplies
, and an off-
E7765
(MIN)
(MIN)
]