MAX1368ECM+ Maxim Integrated Products, MAX1368ECM+ Datasheet - Page 20

• Manufacturer Part Number: MAX1368ECM+
• Description: IC PANEL METER 3.5 DIG 48LQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1368ECM+

• Display Type: LED
• Configuration: 7 Segment
• Interface: Serial
• Digits Or Characters: A/D 3.5 Digits
• Voltage - Supply: 2.7 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -

Microcontroller-Interface, 4.5-/3.5-Digit Panel
Meters with 4–20mA Output
The MAX1366/MAX1368 feature a 5.2V linear regulator.
The 5.2V regulator consists of an op amp and connec-
tions to an external depletion-mode FET. The 5.2V reg-
ulator regulates the loop voltage that powers the
voltage-to-current converter and the rest of the trans-
mitter circuitry. The regulator output voltage is available
at REG_VDD and is given by the equation:
20
Figure 17. MAX1366 Transfer Function—±200mV Range
Figure 16. MAX1366 Transfer Function—±2V Range
5.2V Linear Regulator with Compensation
- 1 - - - -
- 1 - - - -
-19,999
1 - - - -
-19,999
1 - - - -
19,999
19,999
LED
______________________________________________________________________________________
LED
- 0
- 1
- 2
- 0
- 1
- 2
2
1
0
2
1
0
> 4E1Fh
> 4E1Fh
< B1E0h
< B1E0h
RESULT
RESULT
B1E0h
4E1Fh
0002h
0001h
0000h
FFFFh
FFFEh
FFFDh
B1E0h
4E1Fh
0002h
0001h
0000h
FFFFh
FFFEh
FFFDh
ADC
ADC
V
-200mV
REG_VDD
-2V
= 2.54 x V
ANALOG INPUT VOLTAGE
ANALOG INPUT VOLTAGE
-100µV
-10µV
0
0
+100µV
+10µV
REF+
+200mV
+2V
The FET breakdown and saturation voltages determine
the usable range of loop voltages (V
FET parameters such as V
ductance must be chosen so that the op amp output on
the REG_FORCE pin can control the FET operating
point while swinging in the range from VREG_AMP to
REG_VDD. See the Selecting Depletion Mode FET
section in the Applications Information section.
Connect a 0.1µF capacitor between CMP and
REG_FORCE to ensure stable operation of the regulator.
Figure 18. MAX1368 Transfer Function—±200mV Range
Figure 19. MAX1368 Transfer Function—±2V Range
- 1 - - -
- 1 - - -
LED
1 - - -
-1999
1999
LED
1 - - -
-1999
1999
- 0
- 1
- 2
- 0
- 1
- 2
2
1
0
2
1
0
< 830h
RESULT
RESULT
> 7CFh
< 830h
>
7CFh
002h
001h
000h
FFFh
FFEh
FFDh
830h
7CFh
002h
001h
000h
FFFh
FFEh
FFDh
830h
ADC
ADC
7CFh
-200mV
-2V
ANALOG INPUT VOLTAGE
ANALOG INPUT VOLTAGE
GS
-100µV
-1mV
(off), I
0
0
+100µV
+1mV
DSS
EXT
, and transcon-
). The external
+200mV
+2V