Datasheet LT5538 (Analog Devices) - 10

LT5538
APPLICATIONS INFORMATION ENBL (ENABLE) PIN OPERATION
μA. To disable or turn off the chip, this voltage should be below 0.3V. It is important that the voltage applied to the A simplifi ed circuit schematic of the ENBL Pin is shown ENBL pin should never exceed V in Figure 5. The enable voltage necessary to turn on the CC by more than 0.3V. Otherwise, the supply current may be sourced through the LT5538 is 1V. The current drawn by the ENBL pin varies upper ESD protection diode connected at the ENBL pin. with the voltage applied at the pin. When the ENBL volt- Under no circumstances should voltage be applied to the age is 3V, the ENBL current is typically 100 μA. When the ENBL Pin before the supply voltage is applied to the V ENBL voltage is 5V, the ENBL current is increased to 200 CC pin. If this occurs, damage to the IC may result. VCC ENBL 42k 42k 5538 F05
Figure 5. Simplifi ed Schematic of the Enable Circuit TEST CIRCUIT
R4 ENABLE 4.99k LT5538 R5 1 8 C4 ENBL OUT V L1 OUT RF 2 7 O C7 IN+ CAP+ INPUT OPT 1.5nH 3 6 C6 1nF IN– CAP– C8 R1 C5 OPT 4 5 C9 1pF 56Ω 1nF GND VCC OPT 5538 TC01 5V 9 C10 100pF C1 0.1μF C2 100pF
Figure 6. Evaluation Board Circuit Schematic 40MHz to 2.7GHz 3.6GHz to 3.8GHz REF DES VALUE SIZE PART NUMBER REF DES VALUE SIZE PART NUMBER
C1 0.1μF 0603 AVX 0603ZC104KAT C4, C11 12pF 0402 MURATA, GRM155C1H120JZ01B C2, C10 100pF 0402 AVX 0402YC101KAT C8 0.7pF 0402 MURATA, GJR155C1HR70BB01 C4, C5 1nF 0603 AVX 0402ZC102K C5 OPEN C8 1pF 0402 AVX 0402YA1ROCAT
NOTE:
Replace L1 with C11. R1 56 0402 VISHAY, CRCW040256ROFKED R4 4.99k 0402 VISHAY, CRCW04024K99FKED L1 1.5nH 0402 TOKO, LL1005-FH2IN5S 5538f 10