ISL6423 Datasheet, PDF (7/16 Pages) Intersil Corporation – Single Output LNB Supply and Control Voltage Regulator with I2C Interface for Advanced Satellite Set-Top Box Designs DiSEqC 2.0 Compatible

ISL6423
Electrical Specifications
V_CC =
VBOT
12V, T_A = -20°C to
= L, ENT = L, DCL
+85°C, unless otherwise
= L, Iout = 12mA, unless
noted. Typical values
otherwise noted. See
are at T_A
software
= +25°C. EN = H, VTOP
description section for I²C
access to the system. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
THERMAL SHUTDOWN
Temperature Shutdown Threshold
-
150
-
°C
Temperature Shutdown Hysteresis
-
20
-
°C
FLT
FLT (released)
V_O = 6V
-
-
10
μA
FLT (asserted)
I_SINK = 3.2mA
-
-
0.4
V
NOTES:
5. Internal digital soft-start.
6. EXTM, TXT and SELVTOP and addr 0/1 pins have 200k internal pulldown resistors.
7. On exceeding this backward current limit threshold for a period of 100µs, the device enters the dynamic current limit mode and the BCF I²C bit
is set. The dynamic current limit duty ratio during a back current fault is ON = 100µs/OFF = 5ms.
8. In the Dynamic current limit mode the output is ON for 20ms and OFF for 900ms, but remains continuously ON in the Static mode. When tone
is ON, the minimum current limit is 50mA lower than the values indicated in the table. While in the dynamic mode of current limit the overload
trip level is momentarily increased to 990mA during the 20ms ON time to facilitate recovery from overload conditions.
Tone Waveform
ENT
I²C
MSEL
I²C
EXTM
PIN
VOUT
PIN
22kHz
22kHz
Internal Tone
Tr = 10µs typ
22kHz
22kHz
22kHz
22kHz
External Tone
Tr = 10µs typ
Returns to nominal V_OUT ~1 period
after the last EXTM rising edge
T > 55µs;
Internal Tone
NOTES:
9. The signal pin TXT changes the decoder threshold during tone transmit and receive. TTH allows threshold control through I²C.
10. The tone rise and fall times are not shown due to resolution of graphics. It is 10µs typical for 22kHz.
11. The EXTM pins have input thresholds of Vil(max) = 0.8V and Vih(min) = 1.7V
FIGURE 1. TONE WAVEFORM
7
FN9191.2
December 5, 2008