LTC2470 Datasheet, PDF (10/20 Pages) Linear Technology – System Monitoring

LTC2470/LTC2472
APPLICATIONS INFORMATION
t₃
t₁
t₂
CS
D₁₅
D₁₄ D₁₃ D₁₂ D₁₁ D₁₀ D₉
D₈
D₇
D₆
D₅
D₄
D₃ D₂
D₁ D₀
SDO
MSB
LSB
SCK
t_KQ
t_lSCK
EN1 EN2 SPD SLP
SDI
t₄
t₅
t_hSCK
DON’T CARE
Figure 5. Data Input/Output Timing
24702 F05
Table 1. LTC2470/LTC2472 Output Data Format
SINGLE ENDED INPUT V_IN
(LTC2470)
DIFFERENTIAL INPUT VOLTAGE D15
V_IN+ – V_IN– (LTC2472)
(MSB)
D14
D13 D12...D2
D1
D0 CORRESPONDING
(LSB) DECIMAL VALUE
≥V_REF
≥V_REF
1
1
1
1
1
1
65535
V_REF – 1LSB
V_REF – 1LSB
1
1
1
1
1
0
65534
0.75 • V_REF
0.5 • V_REF
1
1
0
0
0
0
49152
0.75 • V_REF – 1LSB
0.5 • V_REF
0.5 • V_REF – 1LSB
0
1
0
1
1
1
1
1
0
0
0
0
0
49151
32768
0.5 • V_REF – 1LSB
–1LSB
0
1
1
1
1
1
32767
0.25 • V_REF
0.25 • V_REF – 1LSB
–0.5 • V_REF
–0.5 • V_REF – 1LSB
0
1
0
0
0
0
0
0
1
1
1
1
16384
16383
0
≤ –V_REF
0
0
0
0
0
0
0
Data Input Format
The data input word is 4 bits long and consists of two en-
able bits (EN1 and EN2) and two programming bits (SPD
and SLP) see Table 2. EN1 is applied to the first rising edge
of SCK after the conversion is complete. Programming is
enabled by setting EN1 = 1 and EN2 = 0.
Table 2. Input Data Format
BIT NAME FUNCTION
EN1 Should Be High (EN1 = 1) in Order to Enable Program Mode
EN2 Should Be Low (EN2 = 0) in Order to Enable Program Mode
SPD Low (SPD = 0, Default) for 250sps, High (SPD = 1) for 1ksps
Output Rate
SLP Low (SLP = 0, Default) for Nap Mode, High (SLP = 1)
for Sleep Mode Where Both Reference and Converter are
Powered Down
*SDI May Also Be Tied Directly to GND to Set Output Rate to 250sps or
V_DD to Set Output Rate to 1ksps. Sleep Mode is Disabled if SDI is Tied to
GND or V_DD.
24702f
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