Linear Technology DC2235A Demo Manual

DESCRIPTION
Demonstration Circuit 2235A has boost and inverting
charge pumps each with a low noise LDO post regulator
featuring the LTC 3265EDHC. The LTC3265 operates with
®
an input voltage from 4.5V to 16V for the boost charge
pump and from 4.5V to 32V for the inverting charge pump.
The demo board provides selectable LDO
nitudes of 5V, 15V, and 24V for each polarity. The demo
board also provides the means to select between low power
Burst Mode operation or low noise constant-frequency
®
PERFORMANCE SUMMARY
SYMBOL PARAMETER
V V Input Voltage Range
IN_P IN_P
V V Input Voltage Range
IN_N IN_N
+ +
V LDO Output Voltage
LDO
– –
V LDO Output Voltage
LDO
+ +
V V Output Voltage Range
OUT OUT
– –
V V Output Voltage Range
OUT OUT
BOARD PHOTO
Low Noise Dual Supply with Boost
and Inverting Charge Pumps
±
output set mag-
Specifications are at T
CONDITIONS
+
V • 2 ≥ LDO Set Point + 0.8V
IN_P
–
V ≤ LDO Set Point – 0.5V
IN_N
MODE = 0V (Const. Freq.)
MODE ≥ 2V (Burst)
MODE = 0V (Const. Freq.)
MODE ≥ 2V (Burst)
DEMO MANUAL DC2235A
mode operation, plus select an operating frequency of
500kHz, 200kHz, or 50kHz.
The LTC3265 data sheet gives a complete description of
the device, operation and application information. The data
sheet must be read in conjunction with this demo manual.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2235A
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
= 25°C
A
MIN TYP
4.5
4.5
1.2
–32
V
IN_P
0.94 • V
–V
–0.94 • V
LTC3265EDHC
MAX
16
32
32
–1.2
• 2
• 2
IN_P
IN_N
IN_N
UNITS
V
V
V
V
V
V
V
V
dc2235af
1