DC1584A - Demo Manual

QUICK START GUIDE FOR
DC1584A
LTC4070EDDB: Simple Low-Iq
Battery Charger/Protector
With NTC Thermistor Input
DESCRIPTION
Demonstration Circuit DC1584A is a Simple Low-Iq Battery Charger/Protector With NTC Thermistor featuring the
LTC®4070EDDB.
PERFORMANCE SUMMARY Specifications are at TA = 25°C
SYMBOL
VBUS
PARAMETER
Input voltage
V(BAT)
Battery Float Voltage
I(BAT)
Battery Charge Current
CONDITIONS
RLIMIT = 169Ω
‘VFLOAT’ jumper on 4.1V, Constant Voltage
Mode. TNTC = 25°C
Constant Current Mode, Vin = 12V, VCC =
3.8V
MIN
10
4.059
TYP
12
49.7
MAX
16
4.141
UNITS
V
V
mA
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 Vcc and GND terminals. See
Figure 2 for proper scope probe technique.
1. Set PS1 = 12V, PS2 = 3.6V, “VFLOAT” (JP2) to
4.1V. Observe I(VBUS) (AM1). The voltage on
the battery is below the LTC4070EDDB’s float
voltage. So all the current is flowing into the battery, and that current is (12V – 3.6V) /169(R1) =
49.7mA.
2. If “LBO” LED lit, decrease PS2 until off. Observe
BAT (VM2). The LBO output goes high when the
battery voltage is below 3.2V, but it has 200300mV of hysteresis. So it may not go low until
3.5V, with Vcc ↑.
3. Increase PS2 until LBO is lit. Observe BAT
(VM2).
4. Increase PS2 until HBO lit. Observe BAT (VM2).
The HBO LED will light when the battery voltage
is within ~50mV of the float voltage.
5. Disconnect PS2, AM2, and 3.6Ω resistor. Observe BAT (VM2). The only limit to the Vcc voltage now is the LTC4070, so the voltage will rise
to the float voltage.
6. Reset the Jumpers to their default position.
1
LTC4070EDDB
AM1
-
+
-
+
AM2
PS1
4.35V - 5.5V supply
1A
+
+
-
+
VM1
3.6Ω
-
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.
Figure 1. Proper Measurement Equipment Setup for DC1584A
GND
VIN
Figure 2. Measuring Input or Output Ripple
2
+
VM2
-
PS2
0V - 5V supply
-
1A
E2
NTC
GND
10V - 15V
E1
E3
C1
1uF
25V
0603
10 %
R6
10k
R5
0
INT
NTC
JP3
EXT
R3
10k
R1
169
1%
2512
3
2
0
R4
NTC
NTCBIAS
ADJ
8
9
5
LBO
HBO
DRV
6
4
7
Charged
Charging
JP5
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
DESIGNER:
G. Barbehenn
ENGINEER:
APPROVED:
CHECKED:
Charged
Charging
TECHNOLOGY
1K
5%
R7
JP6
GND
OPT
BAT
GND
ENTC
E4
E5
E6
GND
LBO
HBO
BAT
75mA
J1
DF3-3P-2DSA
E7
E8
NJC
A PPROVED
DATE
10/15/09
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
1
2
3
DESC RIPTION
PRODUCTION RELEASE
A
REVISION HISTORY
REV
DATE:
X
SIZE
DC1584A
Wednesday , Nov ember 04, 2009
DWG NO.
SHEET
1
OF 1
REV
A
LTC4070EDDB: SIMPLE LOW - Iq BATTERY
CHARGER / PROTECTOR WITH NTC THERMISTOR INPUT
TITLE:
HBO
D2
2
OPT
OPT
HBO LED
R11
1.0
5%
100uF
6.3V
1206
20 %
C3
OPT
R10
1.0
5%
1
G. Barbehenn
DRAWN:
APPROVALS
R8
1K
5%
D1
LBO
CONTRACT NO.
Q1
FDN352AP
OPT
CUSTOMER NOTICE
1
R9
1.0
5%
OPT
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-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.
25 mils clearance
OFF
OFF
Unless noted:
Resistors: Ohms, 0402, 1%, 1/16W
Capacitors: uF, 0402, 10%, 50V
GND
VCC
C2
0.22uF
25V
0805
ON
SHUNT
JP4
ON
JP7
LBO LED
25 mils clearance
GND
U1
LTC4070EDDB
25 mils clearance 1
JP2
VFLOAT
OFF
25 mils clearance
R2
200
4.2V
4.1V
4.0V
JP1
VIN
ON
2
3
VBUS
1
2
ECO
LTC4070EDDB
Figure 3. Schematic
3
LTC4070EDDB
Figure 4. Bill of Materials
4
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