MAX1978ETM+ Maxim Integrated Products, MAX1978ETM+ Datasheet - Page 14

• Manufacturer Part Number: MAX1978ETM+
• Description: IC CNTRLR INT TEMP 48TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1978ETM+

• Applications: Thermoelectric Cooler
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-TQFN Exposed Pad
• Output Voltage Range: - 4.3 V to + 4.3 V
• Output Current: 6 A
• Input Voltage Range: 3 V to 5.5 V
• Input Current: 30 mA
• Power Dissipation: 2105 mW
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Ic Output Type: Current
• Sensing Accuracy Range: ± 1%
• Supply Current: 30mA
• Supply Voltage Range: 3V To 5.5V
• Sensor Case Style: QFN
• No. Of Pins: 48
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Temperature Sensing Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

BFB+ and BFB- output a buffered version of the voltage
that appears on FB+ and FB-, respectively. The buffers
are typically used in conjunction with the undedicated
chopper amplifier to create a monitor for the thermistor
voltage/TEC temperature (Figures 1 and 2). These
buffers are unity-gain chopper amplifiers and exhibit
output ripple. Each output can be either integrated or
filtered to remove the ripple content if necessary.
In addition to the chopper amplifiers at DIFOUT and
BFB_, the MAX1978/MAX1979 include an additional
chopper amplifier at AOUT. This amplifier is uncommit-
Integrated Temperature
Controllers for Peltier Modules
Figure 2. MAX1979 Typical Application Circuit. MAXIN sets the maximum TEC current circuit configured for cooling with NTC ther-
mistor. Current always flow from CS and OS2.
14
Undedicated Chopper-Stabilized Amplifier
THERMISTOR
______________________________________________________________________________________
REF
MONITOR
VOLTAGE
80.6kΩ
Buffered Outputs, BFB+ and BFB-
69.8kΩ
1%
DC CURRENT
UNDERTEMP
OVERTEMP
MONITOR
ALARM
ALARM
105kΩ
1%
1µF
0.01µF
20kΩ
1%
10µF
COMP
UT
OT
ITEC
BFB-
AIN-
AOUT
AIN+
CTLI
FREQ
GND
V
V
DD
DD
PGND2 PGND1
SHDN
10µF
PV
100kΩ
DD
10µF
0.047µF
1
PV
MAX1979
10µF
INTOUT
DD
1µF
2
ted but is intended to provide a temperature-propor-
tional analog output. The thermistor voltage typically is
connected to the undedicated chopper amplifier
through the included buffers BFB+ and BFB-. Figure 3
shows how to configure the undedicated amplifier as a
thermistor voltage monitor. The output voltage at AOUT
is not precisely linear, because the thermistor is not lin-
ear. AOUT is also chopper stabilized and exhibits out-
put ripple and can be either integrated or filtered to
remove the ripple content if necessary.
REF
REF MAXV MAXIN MAXIP
INT-
0.47µF
1MΩ
20kΩ
DIFOUT
OS1
OS2
LX1
LX2
FB-
FB+
CS
4.7µF
100kΩ
3µH
TEC
10kΩ
0.03Ω
REF
THERMAL
FEEDBACK
1µF