Datasheet

LTC6992-1/LTC6992-2/
LTC6992-3/LTC6992-4
17
69921234fc
POL = 1 forces a simple logic inversion, so it changes the
duty cycle range of the LTC6992-3 (making it 100% to 5%)
and LTC6992-4 (making it 95% to 0%). These transfer
functions are detailed in Figure 4.
Table 2. Duty Cycle Ranges
PART NUMBER
DUTY CYCLE RANGE vs V
MOD
= 0V → 1V
POL = 0 POL = 1
LTC6992-1 0% to 100% 100% to 0%
LTC6992-2 5% to 95% 95% to 5%
LTC6992-3 0% to 95% 100% to 5%
LTC6992-4 5% to 100% 95% to 0%
operaTion
Figure 4. PWM Transfer Functions for All LTC6992 Family Parts
V
MOD
/V
SET
(V/V)
0
DUTY CYCLE (%)
100
90
60
40
20
70
80
50
30
10
0
0.4 0.8 0.90.2 0.6
6992 F04a
V
MOD
/V
SET
= 0.9
V
MOD
/V
SET
= 0.1
10.3 0.70.1 0.5
POL = 1
POL = 0
V
MOD
/V
SET
(V/V)
0
DUTY CYCLE (%)
100
90
60
40
20
70
80
50
30
10
0
0.4 0.8 0.90.2 0.6
6992 F04b
10.3 0.70.1 0.5
POL = 1
POL = 0
V
MOD
/V
SET
= 0.86
V
MOD
/V
SET
= 0.14
V
MOD
/V
SET
(V/V)
0
DUTY CYCLE (%)
100
90
60
40
20
70
80
50
30
10
0
0.4 0.8 0.90.2 0.6
6992 F02c
10.3 0.70.1 0.5
POL = 1
POL = 0
V
MOD
/V
SET
= 0.1
V
MOD
/V
SET
= 0.86
V
MOD
/V
SET
(V/V)
0
DUTY CYCLE (%)
100
90
60
40
20
70
80
50
30
10
0
0.4 0.8 0.90.2 0.6
6992 F02d
10.3 0.70.1 0.5
POL = 1
POL = 0
V
MOD
/V
SET
= 0.9
V
MOD
/V
SET
= 0.14
LTC6992-1 LTC6992-2
LTC6992-3 LTC6992-4