IC Phoenix
 
Home ›  MM80 > MAX8520ETP,Smallest TEC Power Drivers for Optical Modules
MAX8520ETP Fast Delivery,Good Price
Part Number:
If you need More Quantity or Better Price,Welcom Any inquiry.
We available via phone +865332716050 Email
Partno Mfg Dc Qty AvailableDescript
MAX8520ETPMAXN/a555avaiSmallest TEC Power Drivers for Optical Modules


MAX8520ETP ,Smallest TEC Power Drivers for Optical ModulesFeaturesThe MAX8520/MAX8521 are designed to drive thermo- 2 Circuit Footprint of 0.31inelectric co ..
MAX8521ETP+T ,Smallest TEC Power Drivers for Optical ModulesFeaturesThe MAX8520/MAX8521 are designed to drive thermo-2♦ Circuit Footprint 0.31inelectric cooler ..
MAX8526EUD+ ,1.425V to 3.6V Input, 2A, 0.2V Dropout LDO Regulators
MAX8526EUD+T ,1.425V to 3.6V Input, 2A, 0.2V Dropout LDO Regulators
MAX8526EUD-T ,1.425V to 3.6V Input, 2A, 0.2V Dropout LDO Regulators
MAX8529EEG , 1.5MHz Dual 180° Out-of-Phase PWM Step-Down Controller with POR
MB81F643242C-10FN ,4 x 512K x 32 bit synchronous dynamic RAMFUJITSU SEMICONDUCTORADVANCED INFO. AE0.1EDATA SHEETMEMORYCMOS4 · 512 K · 32 BITSYNCHRONOUS DYNAMIC ..
MB81F643242C-10FN ,4 x 512K x 32 bit synchronous dynamic RAMfeatures a fully synchronous operation referenced to a positive edge clock whereby all operations a ..
MB81N643289-60FN ,8 x 256K x 32 bit double data rate FCRAMapplications where large memory density and high effective bandwidth arerequired and where a simple ..
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY


MAX8520ETP
Smallest TEC Power Drivers for Optical Modules
General Description
The MAX8520/MAX8521 are designed to drive thermo-
electric coolers (TECs) in space-constrained optical
modules. Both devices deliver ±1.5A output current
and control the TEC current to eliminate harmful current
surges. On-chip FETs minimize external components and
high switching frequency reduces the size of external
components.
The MAX8520 and MAX8521 operate from a single supply
and bias the TEC between the outputs of two synchro-
nous buck regulators. This operation allows for temper-
ature control without “dead zones” or other nonlinearities
at low current. This arrangement ensures that the control
system does not hunt when the set point is very close to
the natural operating point, requiring a small amount of
heating or cooling. An analog control signal precisely
sets the TEC current.
Both devices feature accurate, individually adjustable
heating current limit and cooling current limit, along
with maximum TEC voltage limit to improve the reliability
of optical modules. An analog output signal monitors
the TEC current. A unique ripple cancellation scheme
helps reduce noise.
The MAX8520 is available in a 5mm x 5mm thin QFN
package and its switching frequency is adjustable up to
1MHz through an external resistor. The MAX8521 is also
available in a 5mm x 5mm thin QFN, as well as a space-
saving 3mm x 3mm UCSP™, with a pin-selectable
switching frequency of 500kHz or 1MHz.
Applications

SFF/SFP Modules
Fiber-Optic Laser Modules
Fiber-Optic Network Equipment
ATE
Biotech Lab Equipment
Features
Circuit Footprint of 0.31in2Low-Profile DesignOn-Chip Power MOSFETsHigh-Efficiency Switch-Mode DesignRipple Cancellation for Low NoiseDirect Current Control Prevents TEC Current
Surges
5% Accurate Adjustable Heating/Cooling Current
Limits
2% Accurate TEC Voltage LimitNo Dead Zone or Hunting at Low Output CurrentITEC Monitors TEC Current 1% Accurate Voltage ReferenceSwitching Frequency Up to 1MHz Synchronization (MAX8521)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
Ordering Information

19-2586; Rev 0; 10/02
UCSP is a trademark of Maxim Integrated Products, Inc.ypical Operating Circuit
Pin Configurations appear at end of data sheet.
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
ABSOLUTE MAXIMUM RATINGS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VDDto GND..............................................................-0.3V to +6V
SHDN, MAXV, MAXIP, MAXIN,
CTLI to GND.........................................................-0.3V to +6V
COMP, FREQ, OS1, OS2, CS, REF,
ITEC to GND...........................................-0.3V to (VDD+ 0.3V)
PVDD1, PVDD2 to GND...............................-0.3V to (VDD+ 0.3V)
PVDD1, PVDD2 to VDD...........................................-0.3V to +0.3V
PGND1, PGND2 to GND.......................................-0.3V to +0.3V
COMP, REF, ITEC Short to GND...................................Indefinite
LX Current (Note 1)........................................±2.25A LX Current
Continuous Power Dissipation (TA= +70°C)
20-Pin 5mm x 5mm x 0.9mm QFN (derate 20.8mW/°C
above +70°C) (Note 2)...................................................1.67W
3mm x 3mm UCSP (derate 22mW/°C
above +70°C).................................................................1.75W
Maximum Junction Temperature.....................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering 10s)..................................+300°C
ELECTRICAL CHARACTERISTICS

(VDD= PVDD1 = PVDD2 = SHDN= 5V, 1MHz mode (Note 3). PGND1 = PGND2 = GND, CTLI = MAXV = MAXIP = MAXIN = REF,= 0°C to +85°C, unless otherwise noted. Typical values at TA= +25°C.)
Note 1:
LX has internal clamp diodes to PGND and PVDD. Applications that forward bias these diodes should take care not to exceed
the IC’s package power dissipation limits.
Note 2:
Solder underside metal slug to PC board ground plane.
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
ELECTRICAL CHARACTERISTICS (continued)

(VDD= PVDD1 = PVDD2 = SHDN= 5V, 1MHz mode (Note 3). PGND1 = PGND2 = GND, CTLI = MAXV = MAXIP = MAXIN = REF,= 0°C to +85°C, unless otherwise noted. Typical values at TA= +25°C.)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
ELECTRICAL CHARACTERISTICS

(VDD= PVDD1 = PVDD2 = SHDN= 5V, 1MHz mode (Note 2). PGND1 = PGND2 = GND, CTLI = MAXV = MAXIP = MAXIN = REF, TA=
-40°C to +85°C, unless otherwise noted.) (Note 7)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
ELECTRICAL CHARACTERISTICS (continued)

(VDD= PVDD1 = PVDD2 = SHDN= 5V, 1MHz mode (Note 2). PGND1 = PGND2 = GND, CTLI = MAXV = MAXIP = MAXIN = REF, TA=
Note 3:
Enter 1MHz mode by tying a 60kΩresistor from FREQ to ground for the MAX8520, and tying FREQ to VDDfor the MAX8521.
Note 4:
Includes PFET leakage.
Note 5:
Duty-cycle specification is guaranteed by design and not production tested.
Note 6:
CTLI Gain is defined as:
Note 7:
Specifications to -40°C are guaranteed by design and not production tested.
Typical Operating Characteristics

(VDD= 5V, circuit of Figure 1, TA= +25°C, unless otherwise noted)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
Typical Operating Characteristics (continued)

(VDD= 5V, circuit of Figure 1, TA= +25°C, unless otherwise noted)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
Typical Operating Characteristics (continued)

(VDD= 5V, circuit of Figure 1, TA= +25°C unless otherwise noted)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
Typical Operating Characteristics (continued)

(VDD= 5V, circuit of Figure 1, TA= +25°C unless otherwise noted)
Pin Description
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
Pin Description (continued)
MAX8520/MAX8521
Smallest TEC Power Drivers for
Optical Modules
Detailed Description

The MAX8520/MAX8521 TEC drivers consist of two
switching buck regulators that operate together to directly
control the TEC current. This configuration creates a
differential voltage across the TEC, allowing bidirectional
TEC current for controlled cooling and heating. Controlled
cooling and heating allow accurate TEC temperature con-
trol to within ±0.01°C. The voltage at CTLI directly sets
the TEC current. An external thermal- control loop is typi-
cally used to drive CTLI. Figures 1 and 2 show examples
of the thermal control-loop circuit.
Ripple Cancellation

Switching regulators like those used in the MAX8520/
MAX8521 inherently create ripple voltage on the output.
The dual regulators in the MAX8520/MAX8521 switch in
phase and provide complementary in-phase duty
cycles so ripple waveforms at the TEC are greatly
reduced. This feature suppresses ripple currents and
electrical noise at the TEC to prevent interference with
the laser diode.
Switching Frequency

For the MAX8521, FREQ sets the switching frequency of
the internal oscillator. With FREQ = GND, the oscillator
frequency is set to 500kHz. The oscillator frequency is
1MHz when FREQ = VDD.
For the MAX8520, connect a resistor (REXTin Figure 2)
from FREQ to GND. Choose REXT= 60kΩfor 1MHz
operation, and REXT= 150kΩfor 500kHz operation. For
any intermediary frequency between 500kHz and
1MHz, use the following equation to find the value of
REXTvalue needed for VDD= 5V:
where REXTis the resistance given in kΩ, and fs is the
desired frequency given in MHz. Note that for VDD<
5V, the frequency is reduced slightly, to the extent of
about 7% when VDDreaches 3V. This should be taken
into consideration when selecting the value for REXTat
a known supply voltage.
Voltage and Current-Limit Setting

Both the MAX8520 and MAX8521 provide control of the
maximum differential TEC voltage. Applying a voltage
to MAXV limits the maximum voltage across the TEC.
The voltage at MAXIP and MAXIN sets the maximum
positive and negative current through the TEC. These
current limits can be independently controlled.
Current Monitor Output

ITEC provides a voltage output proportional to the TEC
current (ITEC). See the Functional Diagramfor more
details:
VITEC= 1.5V +(8 ✕(VOS1-VCS))
Reference Output

The MAX8520/MAX8521 include an on-chip voltage ref-
erence. The 1.50V reference is accurate to 1% over
temperature. Bypass REF with 0.1µF to GND. REF can
be used to bias an external thermistor for temperature
sensing as shown in Figures 1 and 2.
Thermal and Fault-Current Protection

The MAX8520/MAX8521 provide fault-current protection
in either FET by turning off both high-side and low-side
FETs when the peak current exceeds 3A in either FET. In
addition, thermal-overload protection limits the total
power dissipation in the chip. When the device’s die junc-
tion temperature exceeds +165°C, an on-chip thermal
sensor shuts down the device. The thermal sensor turns
the device on again after the junction temperature cools
down by 15°C.
Design Procedures
Duty-Cycle Range Selection

By design, the MAX8520/MAX8521 are capable of oper-
ating from 0% to 100% duty cycle, allowing both LX out-
puts to enter dropout. However, as the LX pulse width
narrows, accurate duty-cycle control becomes difficult.
This can result in a low-frequency noise appearing at the
TEC output (typically in the 20kHz to 50kHz range). While
this noise is typically filtered out by the low thermal-loop
bandwidth, for best results, operate the PWM with a pulse
width greater than 200ns. For a 500kHz application, the
recommended duty-cycle range is from 10% to 90%. For
a 1MHz application, it is from 20% to 80%.
ic,good price


TEL:86-533-2716050      FAX:86-533-2716790
   

©2020 IC PHOENIX CO.,LIMITED