Datasheet LT3745-1 (Analog Devices) - 5

LT3745-1
TIMING CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VCC = 3V to 3.6V, VEN/UVLO = 1.5V, VFB = 1.5V, VISP = VISN = 5V, VLEDxx = 1V, RT = 105k, RISET = 60.4k, CCAP = 0.47µF to VIN, CSCKO+/SCKO– = CSDO+/SDO– = 15pF, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
fSCKI Data Shift Clock Frequency l 30 MHz fPWMCK PWMCK Clock Frequency l 25 MHz tWH-CKI SCKI Pulse Duration SCKI = H (Figure 3) l 16 ns tWL-CKI SCKI = L (Figure 3) l 16 ns tWH-PWM PWMCK Pulse Duration PWMCK = H (Figure 4) l 20 ns tWL-PWM PWMCK = L (Figure 4) l 20 ns tWH-LDI LDI Pulse Duration LDI = H (Figure 3) l 20 ns tSU-SDI SDI-SCKI Setup Time SDI – SCKI↑ (Figure 3) l 5 ns tHD-SDI SCKI-SDI Hold Time SCKI↑ – SDI (Figure 3) l 5 ns tSU-LDI SCKI-LDI Setup Time SCKI↓ – LDI↑ (Figure 3) l 5 ns tHD-LDI LDI-SCKI Hold Time LDI↓ – SCKI↑ (Figure 3) l 15 ns tPD-SCK↑ SCKI-SCKO Propagation Delay (Rising) SCKI↑ – SCKO↑ (Figure 3) l 33 50 ns tPD-SCK↓ SCKI-SCKO Propagation Delay (Falling) SCKI↓ – SCKO↓ (Figure 3) l 33 50 ns ∆tPD-SCK SCK Duty Cycle Change ∆tPD-SCK = tPD-SCK↑ – tPD-SCK↓ 0 ns tPD-SD SCKO-SDO Propagation Delay SCKO↑ – SDO (Figure 3) l 2 5 8 ns tPD-PWM PWMCK-LED Propagation Delay PWMCK↑ – ILED (Figure 4) 55 ns tR-SO SCKO/SDO Rise Time CLOAD = 15pF, 10% to 90% 2.6 ns tF-SO SCKO/SDO Fall Time CLOAD = 15pF, 90% to 10% 2.6 ns
Table 1. Test Parameter Equations
I ∆I OUTmax(0−15) – IOUTmin(0−15) LEDC(%) = •100 2•I (1) V OUTavg(0−15) ID = V(DI+ )– V(DI– ) (6) I ∆I OUTavg(0−15) – IOUTcal LEDD(%) = • 100 (2) IOUTcal V(DI+ )+ V(DI– ) V (7) CM = 2  1.205V  IOUTcal = 2500 •   (3) R  ISET  V OD = V(DO+ )– V(DO– ) (8) IOUTn VCC = 3.6V – IOUTn VCC = 3V 100 ∆ILINE(% / V) = • (4) I 0.6V OUTn VCC = 3V V(DO+ )+ V(DO– ) V (9) OS = 2 I 100 ∆I OUTn VOUTn = 3V – IOUTn VOUTn = 1V LOAD (% / V) = • I 2V (5) OUTn VOUTn = 1V 37451f 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Timing Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Typical Application Related Parts