Linear Technology DC1589A Operating and maintenance instructions

1
DESCRIPTION
Demonstration Circuit DC1589A is a Linear Supercap Charger with Current-Limited Ideal Diode and V/I Monitor,
featuring the LTC®4425.
PERFORMANCE SUMMARY Specifications are at T
A
= 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Vin Input Voltage Range 2.7 5.5 V
Icharge Supercap Charge current 2 A
VOUT Supercap Stack Output Voltage 1.2 5.4 V
V(MID) Supercap Midpoint Voltage 0.6 2.7 V
QUICK START PROCEDURE
Refer to Figure 1 for the proper measurement
equipment setup and jumper settings and follow the
procedure below.
NOTE. When measuring the input or output voltage ripple, care
must be taken to avoid a long ground lead on the oscilloscope
probe. Measure the input or output voltage ripple by touching the
probe tip directly across the VBUS or VOUT(x) and GND terminals.
See Figure 2 for proper scope probe technique.
1. Set b[2-0] jmpers (JP3, JP4, JP5) to “1”. Set
MODE (JP6) to “LDO”. Set LD1 to 0A, and PS1
to 5V. Observe VOUT (VM3) = 3.3V, I(VIN)
(AM1) = 2A, and V(PROG) (VM2) = 1V. Note:
The supercapacitor COUT1 will charge in ap-
proximately 0.5 seconds, so please observe
these signals within a few seconds of setting
PS1 to 5V.
2. Set PS1 to 0V. Observe D1 (PFO) should be lit
due to input ‘power failure’
3. Set LD1 to 1A. Observe VOUT. VOUT should
decrease to 0V, in about 1 second.
QUICK START GUID
E
FOR DC1589
A
LTC4425EDD: Linear Supercap
Charger With Current-Limited
Ideal Diode And V/I Monito
r

LTC4425EDD
2
Figure 1. Proper Measurement Equipment Setup for DC1550A
VIN GND
Figure 2. Measuring Input or Output Ripple
PS1 +
4.35V - 5.5V supply
1A -
-
+
VM1
+
-
VM2
+ -
AM1
Note: All connections from equipment should be Kelvin connected directly to the board
pins which they are connected on this diagram and any input or output leads should be
twisted pair.
-
+
VM3
+ -
+ LD1
0V - 5V
- 2
A
AM2

LTC4425EDD
3
Figure 3. Circuit Schematic
b1
01
b2
0
1
0
0
ENABLE
E5
PROG
OFF
0
1
100mA
0
0
C1
2.2uF 6.3V 20%
+
C2
OPT
4.9V
600mA
R5
10k 5%
R7
1k
ON
VIN
JP5
E6
GND
VCLAMP
500mA
A
DC1589A
Monday, November 23, 2009
11
G. Barbehenn
G. Barbehenn
A
LTC4425EDD: LINEAR SUPERCAP CHARGER WITH
CURRENT-LIMITED IDEAL DIODE AND V/I MONITOR
SCHEMATIC
SIZE DATE:
DWG NO. REV
SHEET OF
TITLE:
CONTRACT NO.
APPROVALS
DRAWN: CHECKED: APPROVED: ENGINEER: DESIGNER:
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETSCUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
E4
EN
0
E9
VOUT
0V to 4.9V / 5.4V
Unless Noted: All Resistors are 0402, 1%, 1/16W
R14 511
5%
R9
2k
VIN
+
C3
OPT
1000mA
R12 2.1MEG
V+
COUT1
HS206F 0.55F
5.5V
All Capacitors are 0402, 10%
2000mA
R3
10k 5%
b1
1
JP7 D2
BAT54C
1 2
b0
R13 1k
5%
E8
GND
R6
1MEG
5%
R10 10k JP6
JP1
DISABLE
MODE
R4
1MEG
5%
1
R2 1.2MEG
R8 2.49k
JP4JP3
Normal
1100mA
E7
VMID
1
0
VIN
R1
1.5MEG
E1
VIN
2.7V - 5.5V
LDO
1600mA
*
R11 1.2MEG
1
U1 LT C4425EDD
6 7
11 12
5
4
8
3 9
10
13
1 2
EN PFI_RET
VINVIN
FB
SEL
PFO
PROG PFI
VMID
GND
VOUT VOUT
JP2
0
1500mA
C4
10uF
0603
E2
GND
b0
1
0
Chargecurrent
Char ge cur r ent = 1000 / R p r og
1
0
5.4V
1
b2
OPT
1
Default
EN
0
OPT
1
E3
SEL
0
*
D1
PFO
12
VIN
11
0 1
PFO LED

LTC4425EDD
4
Figure 4. Bill of Materials

Mouser Electronics
Authorized Distributor
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DC1589A