Datasheet

MAX9636 Evaluation Kit
Evaluates: MAX9636
_______________________________________________________________________________________ 3
Table 2. List of LEDS With the Same
Footprint as D1
Since the forward-voltage drop across the LED is
approximately 2V, the applied control voltage ranges
from 0V to VDD1 - 2V.
The silicon pin photodiode (BPW46) has a spectral
bandwidth that ranges from 430nm to 1100nm. Hence,
the EV kit can also be used with LEDs that range from
visible light to infrared light. Table 2 gives a list of LEDs
that have the same footprint as installed LED D1, but with
different wavelengths. When changing D1, replace R8,
R10, R11, and R12 with the appropriate resistor values.
Noninverting Configuration
The EV kit can also be configured as a noninverting
amplifier. Remove D2, R5, C1, and C2 from the EV kit.
Replace R2 with a 0I resistor. The gain is set by the
ratio of R4 and R1 when a voltage (V
INP
) is applied at
the INP
pad and the INM pad is connected to ground by
installing 0I on R9 on the EV kit. The output voltage for
the noninverting configuration is given by the following
equation:
OUT INP OS
R4
V (1 )(V V )
R1
= + +
Inverting Configuration
The EV kit can also be configured as an inverting
amplifier. Remove D2, R2, R5, and R6 from the EV
kit. Install a 0I resistor across R5 and R3. Install the
decoupling capacitors between C4 and C6. The board
is operated in dual supply (Q1.05V to Q2.75V). The gain
is set by the ratio of R4 and R1 when a voltage (V
INM
) is
applied at the INM
pad. The output voltage for the invert-
ing configuration is given by the following equation:
OUT INM OS
R4
V ( )(V V )
R1
= − +
Differential Amplifier
To configure the EV kit as a differential amplifier, remove
D2 and replace R1, R2, R4, and R5 with the appropri-
ate resistors. Remove or choose appropriate equal
capacitors for C1 and C5. When R1 = R2 and R4 = R5,
the CMRR of the differential amplifier is determined by
matching of ratios R1/R2 and R4/R5.
OUT V INP INM
V A (V V )= −
where:
V
R4 R5
A
R1 R2
= =
Shutdown (SHDN)
The MAX9636 (U1) is operational when a shunt is placed
in the 1-2 position on jumper JU1. By placing a shunt in
the 2-3 position, U1 is disabled.
LED Supply
By default, the LED D1 supply uses the same supply
applied at the VDD pad on the EV kit. To use a separate
supply for the LED circuit, move the shunt of jumper JU2
to the 2-3 position and apply a voltage from 2.1V to 5.5V
on the VLED pad on the EV kit.
LED MANUFACTURER
PART NUMBER
WAVELENGTH
(nm)
COLOR
OSRAM LB A6SG-S1T2-35 470 Blue
OSRAM LT A673-Q1R2-25 532 Green
OSRAM LY A676-R1S2-26 587 Yellow
OSRAM LO A676-R1S2-24 606 Orange
OSRAM LA A676-R1S2-1 615 Amber
OSRAM SFH426 880 Infrared
OSRAM SFH425 950 Infrared