Simple power on delay for 3.4v-5v serial device being powered by 5volt VCC
A good solution is to use a proper supervisor circuit that will provide a bulletproof reset pulse regardless of startup conditions. During the 1second delay, nRESET (usually it's active-low) will be asserted.
For example, the MIC803 series from Microchip is available with a 1.12s minimum delay time and suitable voltage settings for 5V and other supply rails such as 3.3V.

You could  use such a circuit (in conjunction with a high-side switch) to control the power to the device, but it's usually better to allow the power to come up but hold the device in reset for the duration.