DESCRIPTION
The SP4446 Evaluation Boards are designed to help the user evaluate the performance of the
SP4446 for use as a single or dual cell input to +5V output DC-DC Converter. The SP4446
have a fixed output voltage programmed to +5V (consult the factory for other voltage options).
The evaluation board is a completely assembled and tested surface mount board which
provides easy probe access points to all SP4446 Inputs and Outputs so that the user can
quickly connect and measure electrical characteristics and waveforms.
SP4446 EVALUATION BOARD SCHEMATIC
Easy Evaluation for the
SP4446 2V to 7V input to 25
to 30V Output
SP4446 provides up to
30mA output current
High Efficiency: up to 80%
SOT23-5 Package & SMT
components for small, low
profile Power Supply
SP4446
Evaluation Board Manual
R1
1.0M
C2
Open
R2
61.9K
J1 SHDN
1
2
3
1.2V to 5V
LOAD
C4
4.7uF
Murata LQH32CN100K11
C1
330pF
Vout
C3
2.2uF
L1 10uH 0.45A
U1 SP4446
1
2
3
4
5
SW
GND
FB
SHDN
Vin
D1
MBR0530
2
USING THE EVALUATION BOARD
1) Powering Up the SP4446 Circuit
The SP4446 Evaluation Board can be powered from inputs from a +1.2V to +7.0V. Connect
with short leads directly to the “Vin” and “Gnd” posts. Monitor the Output Voltage and connect
the Load between the “Vout” post and the 2nd “GND” post.
2) Using the J1 Jumper: Enabling the SP4446 Output and using the Shutdown Mode
The SP4446 output will be Enabled if the J1 Jumper is in the top or pin 1 to 2 position. If J1 is
in the pin 2 to 3 position, the Shutdown pin is brought to GND, which puts the SP4446 in the low
quiescent Shutdown Mode.
3) Selecting the Inductor
In selecting an inductor, the saturation current specified for the inductor needs to be greater
then the SP4446 peak current to avoid saturating the inductor, which would result in a loss in
efficiency and could damage the inductor. The SP4446 evaluation board uses a Murata 10uH
inductor with an Isat value of 450mA and a DCR of 0.39ohms, which easily handles the Ipeak of
350mA of the SP4446 and will deliver high efficiencies. Other inductors could be selected
provided their Isat is greater than the Ipeak of the SP4446.
POWER SUPPLY DATA
3
Figure 1. SP4446 Efficiency Vs Output Current (Vout = 5V)
Figure 2. SP4446 Line/Load Rejection Vs Output Current (Vout = 5V)
Figure 3. SP4446 No-Load Battery Current Vs Vbatt (Vout = 5V)
4
TABLE1: SP4446 LIST OF MATERIALS
ORDERING INFORMATION
Model Temperature Range Package Type
SP4446KEB...............................……… -40°C to +85°C...................SP4446 Evaluation Board
SP4446EK……….....................................-40°C to +85°C......................................5-pin SOT23
Ref. Des. Qty. Manufacturer Part Number Layout Size Component Vendor
LxWxH
1 Sipex Corp. 146-6478-00 1"x1.5" SP4446 Eval PC Board Sipex 978-667-8700
U1 1 Sipex Corp. SP4446EK SOT23-5 5-pin SOT23 Step-Up DC/DC Conv Sipex
C1 1 Murata GRM1885C1H331JA01B 0603 Ceramic 330pF SM Murata 770-436-1300
C2 1 open
C3 1 Murata GRM32RR71E225KC01B 1210 Ceramic 25V 2.2uF SM Murata 770-436-1300
C4 1 Murata GRM31CR61A475KA01B 1206 Ceramic 10V 4.7uF SM Murata 770-436-1300
L1 1 Murata LQH32CN100K11 3.2x2.5x2mm 10uH, 0.45A, 0.39ohm, SM Inductor Murata 770-436-1300
D1 1 On-Semi MBR0530 SOD-123 Schottky Diode 30V, 0.5A On-Semi
R1 1 Panasonic ERJ-3EKF1004 0603 1M ohm 1/8W 1% 0603 SM Digi-Key 800-344-4539
R2 1 Panasonic ERJ-3EKF6192 0603 61.9K ohm 1/8W 1% 0603 SM Digi-Key 800-344-4539
TP 4 Mill-Max 0300-115-01-4727100 .042 Dia Test Point Female Pin Digi-Key 800-344-4539
J1 1 Sullins PTC36SAAN .23x.12 3-Pin Header Digi-Key 800-344-4539
1 Sullins STC02SYAN .2x.1 Shunt Digi-Key 800-344-4539
