MAX152 Evaluation Kit
_______________General Description
The MAX152 evaluation kit (EV kit) is fully assembled, and
provides a proven design and PC board layout for fast,
easy evaluation of the MAX152 at sample rates to
400ksps. An oscillator continuously triggers the converter,
and an LED displays the conversion results. Several
jumpers allow the board to be configured for the various
operating modes of the MAX152, and the board includes
the low-current shutdown circuit shown in the data sheet.
A 16-pin data connector provides easy interface between
the MAX152 EV kit and the user's system.
The MAX152 EV kit can be used to evaluate the 5V
MAX153 at sample rates to 1Msps.
____________________________Features
o
High-Speed 8-Bit ADC
o
Unipolar or Bipolar Input
o
No Clock Circuit Required
o
+3V (MAX152) or +5V (MAX153) Operation
o
Low-Power Shutdown Mode
o
LED Display of Conversion Results
o
3in2 Prototyping Area
o
16-Pin Data Connector for Interface to
External System
MAX152 EV Kit
____________________Component List
DESIGNATION
U1
U2
U3
C1, C3, C6, C7,
C8
C2, C4
C5
D1-D8
Q1
R1
R2, R12
R3-R10
R11
J1, J3
J2, J4, J5, J6,
J7, J8
None
None
None
None
None
QTY
1
1
1
5
DESCRIPTION
______________Ordering Information
PART
MAX152EVKIT-DIP
TEMP. RANGE
0°C to +70°C
BOARD TYPE
Through-Hole
MAX152CPP
74HCT574
ICM7555CPA
0.1µF ceramic capacitors
10µF 16V radial electrolytic
capacitors
100pF ceramic capacitor
Red LEDs
ME12N06EL Nihon N-channel
logic-level MOSFET
300Ω 5% resistor
510kΩ 5% resistors
620Ω 5% resistors
10kΩ 5% resistor
3-pin jumper headers
2-pin jumper headers
Shunts
16-pin ribbon cable connector
3.50" x 4.00" PC board
Rubber feet
MAX152 data sheet and
EV kit manual
The MAX152EVKIT may also be used to evaluate the
MAX153.
To receive a free sample of the
MAX153CPP, call 1-800-998-8800.
2
1
8
1
1
2
8
1
2
6
8
1
1
4
1
______________________________EV Kit
________________________________________________________________________________________ 13
MAX152 Evaluation Kit
MAX152 EV Kit
___________________Quick Reference
The evaluation kit as shipped, is configured for the continuous-
conversion mode. To verify operation, follow these steps:
1. Verify that the jumpers are configured as
described in Table 2.
2. Connect the power supplies (+3V for MAX152,
+5V for MAX153) to the power input connector.
3. Connect an analog input to AIN input.
4. Read conversion results displayed on the LEDs.
J2
Open
Short
1&2
Table 1. Jumper Functions
JUMPER CONNECTION
1&2
J1
2&3
Open
FUNCTION
VREF- connected to the drain
of Q1
VREF- connected to ground
Used when connecting a voltage
source to the VREF- pad
Used when connecting a voltage
source to the VREF+ pad
VREF+ shorted to V
DD
CS
grounded
CS
driven by the ICM7555
Used when an external digital
signal is applied to the
CS
input
Used when driving V
SS
with a
negative source (-5V or -3V)
V
SS
connected to ground
MODE pin open (internally pulled
low)
MODE pin connected to V
DD
ICM7555 circuit disabled
ICM7555 circuit enabled
LED display disabled
LED display enabled
Used when an external digital
input is applied to the
RD
input
RD
driven by the ICM7555
_______________General Description
Jumper Functions
The MAX152 EV kit has several jumpers to alter the
configuration. Table 1 lists the jumpers and their func-
tions. Table 2 gives the jumper selection for a free-run-
ning mode used for board verification.
Note that Table 2's configuration drives both the
RD
and
CS
inputs and sets the MODE pin low. The timing dia-
gram for this configuration is shown in the MAX152 or
MAX153 data sheet. Refer to the data sheet for more
information on the various operating modes.
J3
2&3
Open
Open
Short
J4
J5
Open
Short
Power Requirements
The MAX152 EV kit may be used with either the
MAX152 or MAX153. The MAX152 will operate on sup-
plies as low as 2.7V. The MAX153 operates on +5V or
±5V. The positive supply is also connected to the octal
latch and ICM7555 timer on the board. The LEDs will
cause the positive supply current to approach 60mA
when all are on. The V
SS
input is connected only to the
MAX152/MAX153's V
SS
pin. The V
SS
pin will draw less
than 50µA. Optionally, J4 can be shorted to connect
V
SS
to ground when not using a negative supply.
J6
Open
Short
Open
Short
Open
Short
J7
J8
Table 2. Jumper Selection for Free-Running Mode
JUMPER CONNECTION
J1
J2
J3
J4
J5
J6
J7
J8
2&3
Short
2&3
Short
Open
Short
Short
Short
FUNCTION
VREF- connected to GND
VREF+ connected to V
DD
CS
driven by ICM7555
V
SS
connected to GND. Leave
J4 open if a V
SS
source is used.
MODE pin internally pulled low
Enable the ICM7555
Enable the LED display
RD
driven by ICM7555
MAX152/MAX153 Reference Voltage
The VREF+ and VREF- pins may be connected to any
potential between V
DD
and V
SS
. For single-supply
operation, VREF+ can be connected to V
DD
and VREF-
can be connected to ground. Jumpers (J1 and J2) are
provided for this configuration. If a reference voltage
other than V
DD
or ground is desired, connect the
source to the VREF+ and/or VREF- pads and set J1 and
J2 accordingly. Refer to Table 1 for their use.
MAX152/MAX153 Data Output/Display
The MAX152/MAX153's output is latched and buffered
by a 74HCT574 so it can drive an LED display. The
14
______________________________________________________________________________________
MAX152 Evaluation Kit
LEDs display the output of the MAX152/MAX153 after
each conversion. Removing the J7 shunt will disable
the LED display and lower the positive supply current.
The clock signal for the 74HCT574 is taken off the
RD
input. This latches the MAX152/MAX153 conversion
results on the trailing (positive going) edge of the
RD
signal. This technique works as long as
RD
pulse is
longer than the conversion time of the
MAX152/MAX153.
The ready (RDY) signal can be observed by configur-
ring the board per Table 2 and inserting a 4.7kΩ pull-
up resistor in the location marked R13. The RDY signal
will appear on the
WR/RDY
pin. The resistor is normally
not installed, in order to keep the pin input current as
low as possible.
Shutdown Modes
The function of the power-down pin (PWRDN) is to drop
the MAX152/MAX153's supply current to typically 1µA.
Note, however, that VREF+ will continue to appear to
the source as a 2kΩ resistor, and this resistor draws
current even when the device is in power-down mode.
The addition of MOSFET Q1 opens VREF- to discon-
nect this internal reference resistor and remove its cur-
rent drain. A 510kΩ resistor acts as the pull-up for the
gate of Q1 and
PWRDN.
You can evaluate the power-
down mode simply by grounding the PWRDN pad.
The other chips on the board will continue to draw cur-
rent if they are left enabled. Be sure to disable the LED
display and the ICM7555 circuits for a true measure-
ment.
With the device and LEDs enabled, the supply current
may be 60mA. The current drops to less than 15mA
with the LEDs disabled. Using
PWRDN
with VREF- con-
nected to ground will reduce the current to about
3.5mA. Finally, in power-down mode with VREF- dis-
abled by Q1 and the ICM7555 disabled, the supply
current will typically be less than 50µA. The actual
reading will include the MAX152/MAC153 V
DD
current,
static current for the 74HCT574, and 10µA drawn
through the 510kΩ resistor R2.
MAX152 EV Kit
ICM7555 Circuit
A simple ICM7555 timer circuit on the board provides a
clock for the stand-alone mode. The output can be
connected to the
CS
and
RD
pins through J3 and J8. It
will then trigger a conversion approximately every 2.5µs
when J6 is shorted. J6 is provided to disable the
ICM7555 when evaluating the shutdown currents.
When using external signal sources for
CS
and
RD,
leave jumpers J3 and J8 open. Refer to the data sheet
for timing specifications with external sources.
______________________________________________________________________________________
15
MAX152 EV Kit
MAX152 Evaluation Kit
Figure 1. MAX152 EV Kit Schematic
C4
+
22µF
C3
0.1µF
C1
J4 0.1µF
+
16
C2
22µF
GND
VSS
J7
R3 620Ω
R4 620Ω
R5 620Ω
R6 620Ω
R7 620Ω
R8 620Ω
R9 620Ω
74HCT574
U2
R10 620Ω
0.1µF
J2
J6
R2
510k
R12
510k
D1
D2
D3
D4
D5
D6
D7
D8
R1
300Ω
J5
CS
VREF+
C8
O.1F
1
2 3
VDD
VIN
R13
OPEN
WR/RDY
RD
INT
1
2
3
4
5
6
7
8
9
10
2
3
4
5
6
7
8
9
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
19
18
17
16
15
14
13
12
CE
CLK
D0
D1
D2
D3
D4
D5
D6
D7
MAX152
U1
VDD 20
VIN
VSS 19
D0
D1
PWRDN
18
D7 17
D2
D6 16
D3
WR/RDY
D5 15
D4 14
MODE
13
CS
12
RD
VREF+ 11
INT
GND VREF-
VREF-
J3
3
O
GND
ICM7555
U3
Q1
3
1
J1
2
1
2 3
J8
8 V+
C7
0.1µF
1
RS
CV
THR
DIS
TR
4
5
6
7
2
DATA CONNECTOR
1 D0
D1 2
3
4
D2
D3
5
6
D4
D5 8
7
D6
D7 10
9
CS WR/RD
11
12
INT
RD
13
14
VDD VDD 16
15
GND GND
______________________________________________________________________________________
PWRDN
R11
10kΩ
C5
100pF
MAX152 Evaluation Kit
MAX152 EV Kit
Figure 2. MAX152 EV Kit Component-Side Layout
______________________________________________________________________________________
17
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