ADN8830ACPZ-REEL Analog Devices Inc, ADN8830ACPZ-REEL Datasheet - Page 17

• Manufacturer Part Number: ADN8830ACPZ-REEL
• Description: IC THERMO COOLER CNTRLR 32-LFCSP
• Manufacturer: Analog Devices Inc

Specifications of ADN8830ACPZ-REEL

• Applications: Thermoelectric Cooler
• Current - Supply: 8mA
• Voltage - Supply: 3.3 V ~ 5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-LFCSP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ADN8830ACPZ-REELTR

Although the FETs that drive OUT A alternate between Q1 and
Q2 being on, they have an equivalent series resistance that is
equal to a weighted average of their r
The resistive power loss from the PWM transistors is then
There is also a power loss from the continuing charging and
discharging of the gate capacitances on Q1 and Q2. The power
dissipated due to gate charge loss (P
using the appropriate input capacitance (C
and PMOS. Both transistors are switching, so P
calculated for each one and will be added to find the total power
dissipated from the circuit.
The series resistance of the inductor, R2 from Figure 14, will
also exhibit a power dissipation equal to
Core loss from the inductor arises as a result of nonidealities of
the inductor. Although this is difficult to calculate explicitly, it
can be estimated as 80% of P
cies and 50% of P
Finally, the power dissipated by the ADN8830 is equal to the
current used by the device multiplied by the supply voltage.
Again, this exact equation is difficult to determine as we have
already taken into account some of the current while finding the
gate charge loss. A reasonable estimate is to use 40 mA as the
Part Number
FDW2520C*
IRF7401
IRF7233
FDR6674A
FDR840P
*Recommend transistors in typical application circuit Figure 1.
Part Number
FDW2520C*
Si7904DN
Si7401DN
IRF7401
IRF7404
*Recommend transistors in typical application circuit Figure 1.
REV. C
P
P
P
P
R
FET PWM
GCL
R
LOSS
EQIV
2
,
R
1
2
2
0 8 .
D r
C V
ISS DD
I
R
TEC
RL
EQIV
DS P
P
NMOS
PMOS
NMOS
PMOS
Type
NMOS
PMOS
RL
2
at 100 kHz. Judging conservatively
,
Type
NMOS
PMOS
NMOS
PMOS
NMOS
PMOS
2
1
f
CLK
I
TEC
1
–
RLS
2
D
C
0.17
0.15
0.5
2.2
0.23
0.6
at 1 MHz switching frequen-
GD
r
DS N
GCL
Table V. Recommended FETs for Linear Output Amplifier
Table VI. Recommended FETs for PWM Output Amplifier
DS, ON
(nF)
C
1.33
1.33
1.0
3.5
1.6
1.5
,
ISS
) is
1
(nF)
values.
ISS
Ext. C
2.2
1.0
1.0
) for the NMOS
GCL
GD
should be
(nF)
r
18
35
30
17
22
40
DS,ON
(35)
(36)
(37)
(38)
(39)
(m )
–17–
C
3.3
3.3
3.3
SNUB
total current used by the ADN8830. The power dissipated from
the device itself is
There are certainly other minor mechanisms for power dissipa-
tion in the circuit. However, a rough estimate of the total power
dissipated can be found by summing the preceding power dissi-
pation equations. Efficiency is then found by comparing the
power dissipated with the required output power to the load.
where
The measured efficiency of the system will likely be less than the
calculated efficiency. Measuring the efficiency of the application
circuit is fairly simple but must be done in an exact manner to
ensure the correct numbers are being measured. Using two high
current, low impedance ammeters and two voltmeters, the cir-
cuit should be set up as shown in Figure 15.
Figure 15. Measuring Efficiency of the ADN8830 Circuit
(nF)
P
Efficiency
ADN
Continuous I
6.0
4.5
5.3
7.3
8.7
6.7
8830
r
18
35
22
20
9.5
12
DS, ON
V
POWER SUPPLY
DD
P
V
A
DD
ADN8830
LOAD
(m )
P
LOAD
V
10
P
MAX
LOAD
GND
mA
P
DISS TOT
I
6.0
4.5
8.7
9.5
11.5
10
(A)
MAX
I
LOAD
,
V
(A)
A
V
LOAD
Manufacturer
Fairchild
Fairchild
International Rectifier
International Rectifier
Fairchild
Fairchild
Manufacturer
Fairchild
Fairchild
Vishay Siliconix
Vishay Siliconix
International Rectifier
International Rectifier
LOAD
TEC
ADN8830
(40)
(41)