19-2518; Rev 2; 9/02
MAX1889 Evaluation Kit
General Description
The MAX1889 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains a
step-up switching regulator, a positive three-stage
charge-pump and high-voltage positive linear-regulator
controller, and a negative three-stage charge-pump
and high-voltage negative linear-regulator controller.
The step-up switching circuit is configured for a 9V out-
put and provides up to 200mA from a DC supply volt-
age of 2.7V to 5.5V.
The positive charge-pump and linear regulator are config-
ured for a 20V output using two charge-pump stages pro-
viding up to 10mA. The negative charge pump and linear
regulator are configured for a -7V output using a single
charge-pump stage providing up to 10mA. Power for the
positive charge-pump input can be provided by the DC
input source or the step-up switching regulator output.
Power for the negative charge-pump input can be provid-
ed by the DC input source or the power ground.
The MAX1889 EV kit demonstrates low quiescent cur-
rent and high efficiency (up to 90%) for maximum bat-
tery life. The EV kit features overload protection for the
input and all outputs. Operation at 1MHz allows the use
of tiny surface-mount components. The MAX1889 QFN
package (1.0mm max) with low-profile external compo-
nents allows this circuit to be 1.25mm high.
o
2.7V to 5.5V Input Range
o
Output Voltages
9V Output at 200mA (Step-Up Switching)
20V Output >10mA (Positive Charge-Pump
Regulator)
-7V Output >10mA (Negative Charge-Pump
Regulator)
o
Resistor-Adjustable Outputs
o
Up to Three Positive and Three Negative Charge-
Pump Stages
o
Up to +28V and -22V Linear-Regulated Output
(As Configured)
o
90% Efficiency
o
500kHz/1MHz Step-Up Switching Frequency
o
Overcurrent Protection
o
Low Profile
o
Surface-Mount Components
o
Fully Assembled and Tested
Features
Evaluates: MAX1889
Ordering Information
PART
MAX1889EVKIT
TEMP RANGE
0擄C to +70擄C
IC PACKAGE
16 QFN 5mm x 5mm
Component List
DESIGNATION QTY
C1
1
DESCRIPTION
0.47碌F 鹵10%, 16V X7R
ceramic capacitor (0805)
Taiyo Yuden EMK212BJ474KD
3.3碌F 鹵20%, 6.3V X5R
ceramic capacitors (0805)
Taiyo Yuden JMK212BJ335MG
4.7碌F 鹵20%, 10V X7R
ceramic capacitors (1210)
Taiyo Yuden LMK325BJ475MF
0.01碌F 鹵10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H103K
DESIGNATION QTY
C8
1
DESCRIPTION
220pF 鹵10%, 50V COG
ceramic capacitor (0603)
TDK C1608COG1H221K
0.22碌F 鹵10%, 10V X7R
ceramic capacitor (0603)
Taiyo Yuden LMK107BJ224KA
0.1碌F 鹵10%, 50V X7R
ceramic capacitors (0805)
Taiyo Yuden UMK212BJ104KG
0.15碌F 鹵10%, 50V X7R
ceramic capacitors (1206)
Taiyo Yuden UMK316BJ154KF
C2, C3
2
C9
1
C4, C5, C6
3
C10鈥揅14, C17,
C18, C19,
C21, C22
10
C7
1
C15, C20
2
________________________________________________________________
Maxim Integrated Products
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For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim鈥檚 website at www.maxim-ic.com.
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