MAX6693UP9A+ Maxim Integrated Products, MAX6693UP9A+ Datasheet - Page 17

• Manufacturer Part Number: MAX6693UP9A+
• Description: IC TEMP MONITOR 7CH 20-TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6693UP9A+

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Buffer, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

effect; the measured temperature of the junction tracks
the actual temperature within a conversion cycle.
When measuring temperature with discrete remote tran-
sistors, the best thermal response times are obtained
with transistors in small packages (i.e., SOT23 or SC70).
Take care to account for thermal gradients between the
heat source and the sensor, and ensure that stray air
currents across the sensor package do not interfere with
measurement accuracy. Self-heating does not signifi-
cantly affect measurement accuracy. Remote-sensor
self-heating due to the diode current source is negligible.
The integrating ADC has good noise rejection for low-
frequency signals, such as power-supply hum. In environ-
ments with significant high-frequency EMI, connect an
external 100pF capacitor between DXP_ and DXN_.
Larger capacitor values can be used for added filtering,
but do not exceed 100pF because it can introduce errors
due to the rise time of the switched current source. High-
frequency noise reduction is needed for high-accuracy
remote measurements. Noise can be reduced with careful
PCB layout as discussed in the PCB Layout section.
The slave address for the MAX6693 is shown in Table 11.
Table 10. Remote-Sensors Transistor
Manufacturer (for Channels 2–6)
Note: Discrete transistors must be diode connected (base
shorted to collector).
Table 11. Slave Address
Central Semiconductor (USA)
Rohm Semiconductor (USA)
Samsung (Korea)
Siemens (Germany)
Zetex (England)
A7
1
MANUFACTURER
A6
0
7-Channel Precision Temperature Monitor
A5
0
______________________________________________________________________________________
DEVICE ADDRESS
A4
1
A3
ADC Noise Filtering
1
CMPT3904
SST3904
KST3904-TF
SMBT3904
FMMT3904CT-ND
A2
Slave Address
MODEL NO.
0
A1
1
R/W
A0
with Beta Compensation
Follow these guidelines to reduce the measurement
error when measuring remote temperature:
1) Place the MAX6693 as close as is practical to the
2) Do not route the DXP-DXN lines next to the deflec-
3) Route the DXP and DXN traces in parallel and in close
4) Route through as few vias and crossunders as possi-
5) Use wide traces when practical. 5mil to 10mil traces
6) When the power supply is noisy, add a resistor (up
Figure 5. Recommended DXP-DXN PCB Traces. The two outer
guard traces are recommended if high-voltage traces near the
DXN and DXP traces.
5–10 mils
5–10 mils
remote diode. In noisy environments, such as a com-
puter motherboard, this distance can be 4in to 8in
(typ). This length can be increased if the worst noise
sources are avoided. Noise sources include CRTs,
clock generators, memory buses, and PCI buses.
tion coils of a CRT. Also, do not route the traces
across fast digital signals, which can easily intro-
duce +30°C error, even with good filtering.
proximity to each other. Each parallel pair of traces
should go to a remote diode. Route these traces away
from any higher voltage traces, such as +12VDC.
Leakage currents from PCB contamination must be
dealt with carefully since a 20MΩ leakage path from
DXP to ground causes about +1°C error. If high-volt-
age traces are unavoidable, connect guard traces to
GND on either side of the DXP-DXN traces (Figure 5).
ble to minimize copper/solder thermocouple effects.
are typical. Be aware of the effect of trace resistance on
temperature readings when using long, narrow traces.
to 47Ω) in series with V
GND
DXN
GND
DXP
CC
.
PCB Layout
5–10 mils
MINIMUM
5–10 mils
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