Linear Technology DC1210A Quick Start Manual

DESCRIPTION
Demonstration circuit DC1210A is high voltage sw itching
buck regulator, USB Pow erpath controller and Li-Ion bat-
tery charger. It is based on the LTC4090 and provides
the f ollow ing f unctions:
PERF ORM A NCE SU M M A RY
SYM BOL PARAM ETER
V Input Supply Range - USB
IN
V Input Supply Range - HVIN
HVIN
V HVIN Overvoltage Lockout Threshold
OVLO
Battery Charger
I Charging current
CHG
V V Regulated Output Voltage
FLOAT BAT
I Trickle Charge Current
TRKL
∆V
Recharge threshold
RECHRG
I nput Current
I Input current 100mA mode
LIM
I Input Current 500mA mode
LIM
I Suspend M ode Input Current
IN(SUSP)
OPERA TING PRINCIPL ES
Demo board DC1210A is based on the LTC4090. This
chip manages the pow er supplies that w ould be typical
f or a USB pow ered device. Pow er is input f rom either the
USB cable or f rom a high voltage ( 6V-38V) HVIN input
to an intermediate voltage bus.
The intermediate voltage bus is pow ered f rom USB or
HVIN w hen available, and f rom the battery via an ideal
diode. The battery charger is a CC/ CV timer terminated
type capable of charge currents up to 1.5A
DEMO C IR C U IT DC 1 2 1 0 A
U S B P o w e r Ma n a g e r w ith 2 A
H ig h V o lta g e B u c k R e g u la to r
B u c k Io n / P o ly m e r C h a rg e r
2A buck regulator w ith 6-38V (60V max) input range and
w ith output voltage tracking battery voltage, f ull f eatured
battery charger w ith 4.2V f loat, USB pow er manager that
ensures compliance w ith the USB pow er specif ication
and a pow er path manager f or the battery.
Specifications are at TA = 25°C
CONDI TI ONS
(W ithstands up to 60V w ithout damage)
V = 12V, V = 3.6V , R4 = 71.5kΩ
HVIN BAT
I = 2mA
BAT
V = 2V
BAT
Threshold Voltage Relative to V
FLOAT
HPW R = 0V, R3 = 2.10kΩ
HPW R = 5V, R3 = 2.10kΩ
SUSP = 5V
The HVIN input has overvoltage protection to 60V. The
2A buck regulator connected to HVIN operates at 800kHz
and its output voltage is regulated in the range 3.45V to
4.6V, tracking the battery voltage and typically 0.3V
higher to allow most ef f icient charging.
LTC4090
Q u ic k S ta rt G u id e
L T C 4 0 9 0
M I N TYP M AX
4.35 5.5
6 60
38 41.5 45
650 700 750
4.165 4.200 4.235
49 70 84
-65 -100 -135
86 93 105
452 476 500
50 100
UNI TS
V
V
V
mA
V
mA
mV
mA
mA
µA
1