Rainbow Electronics DS1875 - Manual (Page 12)

DS1875
PON Triplexer and SFP Controller
12 ______________________________________________________________________________________
PWM DAC DNL
DS1875 toc19
DAC SETTING (DEC)
DAC DNL (LSB)
224 192 32 64 96 128 160
-0.75
-0.50
-0.25
0
0.25
0.50
0.75
1.00
-1.00
0 256
PWM DAC INL
DS1875 toc20
DAC SETTING (DEC)
DAC INL (LSB)
224 192 32 64 96 128 160
-0.75
-0.50
-0.25
0
0.25
0.50
0.75
1.00
-1.00
0 256
M3QT DAC DNL
DS1875 toc21
DAC SETTING (DEC)
DAC DNL (LSB)
224 192 32 64 96 128 160
-0.75
-0.50
-0.25
0
0.25
0.50
0.75
1.00
-1.00
0 256
M3QT DAC INL
DS1875 toc22
DAC SETTING (dec)
DAC INL (LSB)
224 192 32 64 96 128 160
-0.75
-0.50
-0.25
0
0.25
0.50
0.75
1.00
-1.00
0 256
SW CURRENT INTO BSS123 FET
FREQUENCY = 1050kHz 50% DUTY CYCLE
DS1875 toc23
100ns/div
0V
1V/div
0mA
10mA/div
SW
CURRENT
SW
PWM DAC CHANGING FROM 00h TO 80h
R
COMP
= 24.3k Ω, C
COMP
= 220nF
DS1875 toc24
5ms/div
0V
20V/div
0V
0V
10%/div
0%
200mV/div
200mV/div
V OUT
COMP
DUTY CYCLE
FB
SWITCHING WAVEFORMS
V IN = 3.3V, V OUT ~ 90V, I OUT ~ 1.25mA,
C2 = 0.1 μF
DS1875 toc25
2 μs/div
0V
5V/div
0V
0V
0mA
50V/div
100mV/div
100mA/div
SW
INDUCTOR
VOLTAGE
INDUCTOR
CURRENT
V OUT RIPPLE (AC-COUPLED)
Typical Operating Characteristics (continued)
(V CC = +2.85V to +3.9V, T A = +25°C, unless otherwise noted.)